

<!-- Created by Merrill Corporation -->
<!--Generated by IRIS XBRL Generation Engine-->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureAcquisitionDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureAcquisitionDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureAcquisitionDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureAcquisitionDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureCapitalStructureDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureCapitalStructureDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails3" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureStockPlansDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureStockPlansDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureCreditFacilityDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureCreditFacilityDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureAccumulatedOtherComprehensiveIncomeDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureRestructuringChargesDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureRestructuringChargesDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureBasisOfPresentationDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureBasisOfPresentationDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureAcquisitionTables" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureAcquisitionTables" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureSubsequentEventsReviewDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureSubsequentEventsReviewDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureGoodwillAndIntangiblesDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureGoodwillAndIntangiblesDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureStockholdersEquityDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureStockholdersEquityDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureStockPlansDetails4" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureStockPlansDetails4" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureStockPlansDetails3" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureStockPlansDetails3" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosurePropertyAndEquipmentDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosurePropertyAndEquipmentDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureStockPlansDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureStockPlansDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureIncomeTaxesDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureIncomeTaxesDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureValuationAndQualifyingAccountsDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureValuationAndQualifyingAccountsDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails6" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails6" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureLegalMattersDetails" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureLegalMattersDetails" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails2" xlink:type="simple" xlink:href="sncr-20131231.xsd#DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails2" />
  <link:roleRef roleURI="http://www.synchronoss.com/role/StatementOfStockholdersEquity" xlink:type="simple" xlink:href="sncr-20131231.xsd#StatementOfStockholdersEquity" />
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails">
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:label="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:title="SummaryOfSignificantAccountingPoliciesLineItems" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:label="loc_sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:title="SummaryOfSignificantAccountingPoliciesTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="Definition : loc_us-gaap_StatementScenarioAxis to loc_us-gaap_ScenarioUnspecifiedDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestatementAdjustmentMember" xlink:label="loc_us-gaap_RestatementAdjustmentMember" xlink:title="RestatementAdjustmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:to="loc_us-gaap_RestatementAdjustmentMember" xlink:title="Definition : loc_us-gaap_ScenarioUnspecifiedDomain to loc_us-gaap_RestatementAdjustmentMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_us-gaap_AccountsReceivableNetCurrent" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesTable" xlink:to="loc_us-gaap_StatementScenarioAxis" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesTable to loc_us-gaap_StatementScenarioAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:title="PrepaidExpenseAndOtherAssetsCurrent" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill" xlink:title="Goodwill" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_us-gaap_Goodwill" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_us-gaap_Goodwill" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent" xlink:title="DeferredRevenueCurrent" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems" xlink:to="loc_us-gaap_DeferredRevenueCurrent" xlink:title="Definition : loc_sncr_SummaryOfSignificantAccountingPoliciesLineItems to loc_us-gaap_DeferredRevenueCurrent" xlink:type="arc" use="optional" order="6" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:title="FairValueByFairValueHierarchyLevelAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:title="Definition : loc_us-gaap_FairValueByFairValueHierarchyLevelAxis to loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpeechCycleIncMember" xlink:label="loc_sncr_SpeechCycleIncMember" xlink:title="SpeechCycleIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpeechCycleIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpeechCycleIncMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member" xlink:title="FairValueInputsLevel1Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaap_FairValueInputsLevel1Member" xlink:title="Definition : loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain to loc_us-gaap_FairValueInputsLevel1Member" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:label="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:title="AssetsAndLiabilitiesFairValueDisclosureAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MoneyMarketFundsAtCarryingValue" xlink:label="loc_us-gaap_MoneyMarketFundsAtCarryingValue" xlink:title="MoneyMarketFundsAtCarryingValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:to="loc_us-gaap_MoneyMarketFundsAtCarryingValue" xlink:title="Definition : loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract to loc_us-gaap_MoneyMarketFundsAtCarryingValue" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:title="AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:title="AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract to loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesWithinOneYear" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesWithinOneYear" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesWithinOneYear" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesWithinOneYear" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesWithinOneYear" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesWithinOneYear" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesWithinOneYear" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesWithinOneYear" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesWithinOneYear" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesWithinOneYear" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="BusinessCombinationConsiderationTransferredAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionContingentConsiderationSettlementCashPaid" xlink:label="loc_sncr_BusinessAcquisitionContingentConsiderationSettlementCashPaid" xlink:title="BusinessAcquisitionContingentConsiderationSettlementCashPaid" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_sncr_BusinessAcquisitionContingentConsiderationSettlementCashPaid" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_sncr_BusinessAcquisitionContingentConsiderationSettlementCashPaid" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain_1" xlink:title="FairValueMeasurementsFairValueHierarchyDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="FairValueMeasurementsFairValueHierarchyDomain_1" xlink:title="Definition : loc_us-gaap_FairValueByFairValueHierarchyLevelAxis to loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member" xlink:title="FairValueInputsLevel2Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaap_FairValueInputsLevel2Member" xlink:title="Definition : loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain to loc_us-gaap_FairValueInputsLevel2Member" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CertificatesOfDepositMunicipalAndCorporateBondsEnhancedIncomeFunds" xlink:label="loc_sncr_CertificatesOfDepositMunicipalAndCorporateBondsEnhancedIncomeFunds" xlink:title="CertificatesOfDepositMunicipalAndCorporateBondsEnhancedIncomeFunds" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:to="loc_sncr_CertificatesOfDepositMunicipalAndCorporateBondsEnhancedIncomeFunds" xlink:title="Definition : loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract to loc_sncr_CertificatesOfDepositMunicipalAndCorporateBondsEnhancedIncomeFunds" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:title="AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract to loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesAfterOneThroughFiveYears" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesAfterOneThroughFiveYears" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesAfterOneThroughFiveYears" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesAfterOneThroughFiveYears" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainDebtMaturitiesAfterOneThroughFiveYears" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesAfterOneThroughFiveYears" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesAfterOneThroughFiveYears" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesAfterOneThroughFiveYears" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesAfterOneThroughFiveYears" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossesDebtMaturitiesAfterOneThroughFiveYears" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" xlink:title="FairValueInputsLevel3Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaap_FairValueInputsLevel3Member" xlink:title="Definition : loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain to loc_us-gaap_FairValueInputsLevel3Member" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:title="BusinessCombinationContingentConsiderationLiability" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:title="Definition : loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract to loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount" xlink:label="loc_us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount" xlink:title="FairValueAssetsLevel1ToLevel2TransfersAmount" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:title="AvailableForSaleSecuritiesDebtSecurities" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract to loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedGainAccumulatedInInvestments" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" xlink:label="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" xlink:title="AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:to="loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" xlink:title="Definition : loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract to loc_sncr_AvailableForSaleSecuritiesGrossUnrealizedLossAccumulatedInInvestments" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:title="EstimateOfFairValueFairValueDisclosureMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:title="Definition : loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain to loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsNet" xlink:label="loc_us-gaap_AssetsNet" xlink:title="AssetsNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract" xlink:to="loc_us-gaap_AssetsNet" xlink:title="Definition : loc_sncr_AssetsAndLiabilitiesFairValueDisclosureAbstract to loc_us-gaap_AssetsNet" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount" xlink:label="loc_us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount" xlink:title="FairValueAssetsLevel2ToLevel1TransfersAmount" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:type="arc" use="optional" order="5" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainAbstract" xlink:type="arc" use="optional" order="6" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLossAbstract" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:title="ProceedsFromSaleAndMaturityOfMarketableSecurities" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesGainLoss" xlink:label="loc_us-gaap_MarketableSecuritiesGainLoss" xlink:title="MarketableSecuritiesGainLoss" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_MarketableSecuritiesGainLoss" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_MarketableSecuritiesGainLoss" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:title="BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="arc" use="optional" order="11" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="Definition : loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:type="arc" use="optional" order="12" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_FusionOneIncorporatedMember" xlink:label="loc_sncr_FusionOneIncorporatedMember" xlink:title="FusionOneIncorporatedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_FusionOneIncorporatedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_FusionOneIncorporatedMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CompletionOfEarnOutMilestonesCashPaid" xlink:label="loc_sncr_CompletionOfEarnOutMilestonesCashPaid" xlink:title="CompletionOfEarnOutMilestonesCashPaid" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_sncr_CompletionOfEarnOutMilestonesCashPaid" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_sncr_CompletionOfEarnOutMilestonesCashPaid" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:label="loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:title="SapienceKnowledgeSystemsIncorporatedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:type="arc" use="optional" order="8001" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureAcquisitionDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="Definition : loc_us-gaap_StatementScenarioAxis to loc_us-gaap_ScenarioUnspecifiedDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ContingentConsiderationByTypeAxis" xlink:label="loc_us-gaap_ContingentConsiderationByTypeAxis" xlink:title="ContingentConsiderationByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain" xlink:title="ContingentConsiderationTypeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain" xlink:title="Definition : loc_us-gaap_ContingentConsiderationByTypeAxis to loc_us-gaap_ContingentConsiderationTypeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StrumsoftIncMember" xlink:label="loc_sncr_StrumsoftIncMember" xlink:title="StrumsoftIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_StrumsoftIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_StrumsoftIncMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestatementAdjustmentMember" xlink:label="loc_us-gaap_RestatementAdjustmentMember" xlink:title="RestatementAdjustmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:to="loc_us-gaap_RestatementAdjustmentMember" xlink:title="Definition : loc_us-gaap_ScenarioUnspecifiedDomain to loc_us-gaap_RestatementAdjustmentMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ContingentConsiderationPayableUponAchievingQuarterlyRevenueMember" xlink:label="loc_sncr_ContingentConsiderationPayableUponAchievingQuarterlyRevenueMember" xlink:title="ContingentConsiderationPayableUponAchievingQuarterlyRevenueMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain" xlink:to="loc_sncr_ContingentConsiderationPayableUponAchievingQuarterlyRevenueMember" xlink:title="Definition : loc_us-gaap_ContingentConsiderationTypeDomain to loc_sncr_ContingentConsiderationPayableUponAchievingQuarterlyRevenueMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:label="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:title="BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="Definition : loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain_1" xlink:title="ScenarioUnspecifiedDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain_1" xlink:title="Definition : loc_us-gaap_StatementScenarioAxis to loc_us-gaap_ScenarioUnspecifiedDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ContingentConsiderationTypeDomain" xlink:label="ContingentConsiderationTypeDomain_2" xlink:title="ContingentConsiderationTypeDomain_2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis" xlink:to="ContingentConsiderationTypeDomain_2" xlink:title="Definition : loc_us-gaap_ContingentConsiderationByTypeAxis to loc_us-gaap_ContingentConsiderationTypeDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NewbaySoftwareLimitedMember" xlink:label="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="NewbaySoftwareLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_NewbaySoftwareLimitedMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ContingentConsiderationPayableUponAchievingAnnualRevenueMember" xlink:label="loc_sncr_ContingentConsiderationPayableUponAchievingAnnualRevenueMember" xlink:title="ContingentConsiderationPayableUponAchievingAnnualRevenueMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain" xlink:to="loc_sncr_ContingentConsiderationPayableUponAchievingAnnualRevenueMember" xlink:title="Definition : loc_us-gaap_ContingentConsiderationTypeDomain to loc_sncr_ContingentConsiderationPayableUponAchievingAnnualRevenueMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:title="BusinessAcquisitionPercentageOfVotingInterestsAcquired" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="Definition : loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_ContingentConsiderationByTypeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_ContingentConsiderationByTypeAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="BusinessCombinationConsiderationTransferredAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:title="BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableUponCompletionOfMilestone" xlink:label="loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableUponCompletionOfMilestone" xlink:title="BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableUponCompletionOfMilestone" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableUponCompletionOfMilestone" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableUponCompletionOfMilestone" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_StatementScenarioAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_StatementScenarioAxis" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:title="BusinessCombinationContingentConsiderationLiability" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableToExistingEmployeesUponCompletionOfMilestone" xlink:label="loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableToExistingEmployeesUponCompletionOfMilestone" xlink:title="BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableToExistingEmployeesUponCompletionOfMilestone" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableToExistingEmployeesUponCompletionOfMilestone" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationPotentialMaximumUndiscountedContingentConsiderationPayableToExistingEmployeesUponCompletionOfMilestone" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccruedExpenses" xlink:label="loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccruedExpenses" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccruedExpenses" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:to="loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccruedExpenses" xlink:title="Definition : loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract to loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccruedExpenses" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionCostOfAcquiredEntityClosingAdjustment" xlink:label="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityClosingAdjustment" xlink:title="BusinessAcquisitionCostOfAcquiredEntityClosingAdjustment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityClosingAdjustment" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_sncr_BusinessAcquisitionCostOfAcquiredEntityClosingAdjustment" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross" xlink:title="PaymentsToAcquireBusinessesGross" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_PaymentsToAcquireBusinessesGross" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:title="Definition : loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:title="BusinessCombinationConsiderationTransferred1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionCostOfAcquiredEntityConsiderationWorkingCapitalSurplus" xlink:label="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityConsiderationWorkingCapitalSurplus" xlink:title="BusinessAcquisitionCostOfAcquiredEntityConsiderationWorkingCapitalSurplus" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityConsiderationWorkingCapitalSurplus" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionCostOfAcquiredEntityConsiderationWorkingCapitalSurplus" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:title="BusinessCombinationAcquisitionRelatedCosts" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:title="Definition : loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract to loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionCostOfAcquiredEntityIncludingWorkingCapitalSurplus" xlink:label="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityIncludingWorkingCapitalSurplus" xlink:title="BusinessAcquisitionCostOfAcquiredEntityIncludingWorkingCapitalSurplus" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityIncludingWorkingCapitalSurplus" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionCostOfAcquiredEntityIncludingWorkingCapitalSurplus" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:title="BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:title="BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuablePortionConsideredAsPurchasePriceBasedOnClosingStockPrice" xlink:label="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuablePortionConsideredAsPurchasePriceBasedOnClosingStockPrice" xlink:title="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuablePortionConsideredAsPurchasePriceBasedOnClosingStockPrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuablePortionConsideredAsPurchasePriceBasedOnClosingStockPrice" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuablePortionConsideredAsPurchasePriceBasedOnClosingStockPrice" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionCostOfAcquiredEntityRemainingEquityInterestsIssuedAndIssuableAmortizationTerm" xlink:label="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityRemainingEquityInterestsIssuedAndIssuableAmortizationTerm" xlink:title="BusinessAcquisitionCostOfAcquiredEntityRemainingEquityInterestsIssuedAndIssuableAmortizationTerm" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionCostOfAcquiredEntityRemainingEquityInterestsIssuedAndIssuableAmortizationTerm" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionCostOfAcquiredEntityRemainingEquityInterestsIssuedAndIssuableAmortizationTerm" xlink:type="arc" use="optional" order="11" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationContingentConsiderationArrangementsPotentialCashPayment" xlink:label="loc_sncr_BusinessCombinationContingentConsiderationArrangementsPotentialCashPayment" xlink:title="BusinessCombinationContingentConsiderationArrangementsPotentialCashPayment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationContingentConsiderationArrangementsPotentialCashPayment" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationContingentConsiderationArrangementsPotentialCashPayment" xlink:type="arc" use="optional" order="12" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill" xlink:title="Goodwill" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_Goodwill" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_Goodwill" xlink:type="arc" use="optional" order="13" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:type="arc" use="optional" order="14" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionPurchasePriceAllocationAdjustmentAbstract" xlink:type="arc" use="optional" order="15" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpeechCycleIncMember" xlink:label="loc_sncr_SpeechCycleIncMember" xlink:title="SpeechCycleIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpeechCycleIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpeechCycleIncMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionContingentConsiderationPotentialPayment" xlink:label="loc_sncr_BusinessAcquisitionContingentConsiderationPotentialPayment" xlink:title="BusinessAcquisitionContingentConsiderationPotentialPayment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionContingentConsiderationPotentialPayment" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionContingentConsiderationPotentialPayment" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionContingentConsiderationPotentialEmployeeCompensation" xlink:label="loc_sncr_BusinessAcquisitionContingentConsiderationPotentialEmployeeCompensation" xlink:title="BusinessAcquisitionContingentConsiderationPotentialEmployeeCompensation" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionContingentConsiderationPotentialEmployeeCompensation" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionContingentConsiderationPotentialEmployeeCompensation" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPaymentToAcquireSharesAndWarrants" xlink:label="loc_sncr_BusinessAcquisitionPaymentToAcquireSharesAndWarrants" xlink:title="BusinessAcquisitionPaymentToAcquireSharesAndWarrants" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionPaymentToAcquireSharesAndWarrants" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionPaymentToAcquireSharesAndWarrants" xlink:type="arc" use="optional" order="8002" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsDiscountRate" xlink:label="loc_us-gaap_FairValueInputsDiscountRate" xlink:title="FairValueInputsDiscountRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_FairValueInputsDiscountRate" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_FairValueInputsDiscountRate" xlink:type="arc" use="optional" order="8003" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationNumberOfMilestonePayments" xlink:label="loc_sncr_BusinessCombinationNumberOfMilestonePayments" xlink:title="BusinessCombinationNumberOfMilestonePayments" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationNumberOfMilestonePayments" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationNumberOfMilestonePayments" xlink:type="arc" use="optional" order="8004" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationThresholdRevenue" xlink:label="loc_sncr_BusinessCombinationThresholdRevenue" xlink:title="BusinessCombinationThresholdRevenue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationThresholdRevenue" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationThresholdRevenue" xlink:type="arc" use="optional" order="8005" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationPotentialCompensativePayment" xlink:label="loc_sncr_BusinessCombinationPotentialCompensativePayment" xlink:title="BusinessCombinationPotentialCompensativePayment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationPotentialCompensativePayment" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationPotentialCompensativePayment" xlink:type="arc" use="optional" order="8006" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationPercentageOfEmployeesEntityMinimum" xlink:label="loc_sncr_BusinessCombinationPercentageOfEmployeesEntityMinimum" xlink:title="BusinessCombinationPercentageOfEmployeesEntityMinimum" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessCombinationPercentageOfEmployeesEntityMinimum" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessCombinationPercentageOfEmployeesEntityMinimum" xlink:type="arc" use="optional" order="8007" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureAcquisitionDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis to loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StrumsoftIncMember" xlink:label="loc_sncr_StrumsoftIncMember" xlink:title="StrumsoftIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_StrumsoftIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_StrumsoftIncMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember" xlink:title="TradeNamesMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_TradeNamesMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_TradeNamesMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:title="FiniteLivedIntangibleAssetsNetAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:title="FiniteLivedIntangibleAssetsGross" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="FiniteLivedIntangibleAssetsMajorClassNameDomain_1" xlink:title="FiniteLivedIntangibleAssetsMajorClassNameDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="FiniteLivedIntangibleAssetsMajorClassNameDomain_1" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis to loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NewbaySoftwareLimitedMember" xlink:label="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="NewbaySoftwareLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_NewbaySoftwareLimitedMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember" xlink:title="OrderOrProductionBacklogMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_OrderOrProductionBacklogMember" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember" xlink:title="CustomerRelationshipsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_CustomerRelationshipsMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_CustomerRelationshipsMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:title="FiniteLivedIntangibleAssetsNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayableAndAccruedLiabilities" xlink:label="loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayableAndAccruedLiabilities" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayableAndAccruedLiabilities" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayableAndAccruedLiabilities" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayableAndAccruedLiabilities" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:label="loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:type="arc" use="optional" order="11" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:type="arc" use="optional" order="12" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:type="arc" use="optional" order="13" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:type="arc" use="optional" order="14" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNetExcludingGoodwill" xlink:label="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNetExcludingGoodwill" xlink:title="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNetExcludingGoodwill" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNetExcludingGoodwill" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNetExcludingGoodwill" xlink:type="arc" use="optional" order="15" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill" xlink:title="Goodwill" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_Goodwill" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_Goodwill" xlink:type="arc" use="optional" order="16" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:title="BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:type="arc" use="optional" order="17" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:title="AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:type="arc" use="optional" order="18" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:title="FiniteLivedIntangibleAssetUsefulLife" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="arc" use="optional" order="19" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AmortizationAcquiredIntangibleAssets" xlink:label="loc_sncr_AmortizationAcquiredIntangibleAssets" xlink:title="AmortizationAcquiredIntangibleAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_AmortizationAcquiredIntangibleAssets" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_AmortizationAcquiredIntangibleAssets" xlink:type="arc" use="optional" order="20" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpeechCycleIncMember" xlink:label="loc_sncr_SpeechCycleIncMember" xlink:title="SpeechCycleIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpeechCycleIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpeechCycleIncMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember" xlink:title="DevelopedTechnologyRightsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_DevelopedTechnologyRightsMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionPurchasePriceAllocationDeferredIncomeTaxesAssetNet" xlink:label="loc_sncr_BusinessAcquisitionPurchasePriceAllocationDeferredIncomeTaxesAssetNet" xlink:title="BusinessAcquisitionPurchasePriceAllocationDeferredIncomeTaxesAssetNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="loc_sncr_BusinessAcquisitionPurchasePriceAllocationDeferredIncomeTaxesAssetNet" xlink:title="Definition : loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract to loc_sncr_BusinessAcquisitionPurchasePriceAllocationDeferredIncomeTaxesAssetNet" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:title="BusinessAcquisitionProFormaInformationAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:title="BusinessAcquisitionsProFormaRevenue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract to loc_us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="BusinessCombinationConsiderationTransferredAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:title="BusinessAcquisitionsProFormaNetIncomeLoss" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract to loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessAcquisitionSurplusPaymentForWorkingCapital" xlink:label="loc_sncr_BusinessAcquisitionSurplusPaymentForWorkingCapital" xlink:title="BusinessAcquisitionSurplusPaymentForWorkingCapital" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_BusinessAcquisitionSurplusPaymentForWorkingCapital" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_BusinessAcquisitionSurplusPaymentForWorkingCapital" xlink:type="arc" use="optional" order="8002" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenue" xlink:label="loc_us-gaap_DeferredRevenue" xlink:title="DeferredRevenue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_DeferredRevenue" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_DeferredRevenue" xlink:type="arc" use="optional" order="8003" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureCapitalStructureDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems" xlink:title="ClassOfStockLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable" xlink:title="ScheduleOfStockByClassTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_ScheduleOfStockByClassTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="loc_us-gaap_ClassOfStockDomain" xlink:title="Definition : loc_us-gaap_StatementClassOfStockAxis to loc_us-gaap_ClassOfStockDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="loc_us-gaap_PlanNameDomain" xlink:title="Definition : loc_us-gaap_PlanNameAxis to loc_us-gaap_PlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember" xlink:title="CommonStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_us-gaap_CommonStockMember" xlink:title="Definition : loc_us-gaap_ClassOfStockDomain to loc_us-gaap_CommonStockMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2000PlanMember" xlink:label="loc_sncr_StockIncentive2000PlanMember" xlink:title="StockIncentive2000PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2000PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2000PlanMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable" xlink:to="loc_us-gaap_StatementClassOfStockAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfStockByClassTable to loc_us-gaap_StatementClassOfStockAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_1" xlink:title="ClassOfStockDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_1" xlink:title="Definition : loc_us-gaap_StatementClassOfStockAxis to loc_us-gaap_ClassOfStockDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2006PlanMember" xlink:label="loc_sncr_StockIncentive2006PlanMember" xlink:title="StockIncentive2006PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2006PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2006PlanMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NumberOfVotesPerShare" xlink:label="loc_sncr_NumberOfVotesPerShare" xlink:title="NumberOfVotesPerShare" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_sncr_NumberOfVotesPerShare" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_sncr_NumberOfVotesPerShare" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable" xlink:to="loc_us-gaap_PlanNameAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfStockByClassTable to loc_us-gaap_PlanNameAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2010PlanMember" xlink:label="loc_sncr_StockIncentive2010PlanMember" xlink:title="StockIncentive2010PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2010PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2010PlanMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Dividends" xlink:label="loc_us-gaap_Dividends" xlink:title="Dividends" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_Dividends" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_Dividends" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued" xlink:title="CommonStockSharesIssued" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_CommonStockSharesIssued" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_CommonStockSharesIssued" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" xlink:title="CommonStockSharesOutstanding" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_CommonStockSharesOutstanding" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_CommonStockSharesOutstanding" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:title="CommonStockCapitalSharesReservedForFutureIssuance" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding" xlink:title="PreferredStockSharesOutstanding" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding" xlink:title="Definition : loc_us-gaap_ClassOfStockLineItems to loc_us-gaap_PreferredStockSharesOutstanding" xlink:type="arc" use="optional" order="7" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="loc_us-gaap_ConcentrationRiskLineItems" xlink:title="ConcentrationRiskLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="loc_us-gaap_ConcentrationRiskTable" xlink:title="ConcentrationRiskTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_ConcentrationRiskTable" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_ConcentrationRiskTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:title="ConcentrationRiskByBenchmarkAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:title="ConcentrationRiskBenchmarkDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:title="Definition : loc_us-gaap_ConcentrationRiskByBenchmarkAxis to loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:title="ConcentrationRiskByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:title="ConcentrationRiskTypeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:title="Definition : loc_us-gaap_ConcentrationRiskByTypeAxis to loc_us-gaap_ConcentrationRiskTypeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorCustomersAxis" xlink:label="loc_us-gaap_MajorCustomersAxis" xlink:title="MajorCustomersAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="loc_us-gaap_NameOfMajorCustomerDomain" xlink:title="NameOfMajorCustomerDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorCustomersAxis" xlink:to="loc_us-gaap_NameOfMajorCustomerDomain" xlink:title="Definition : loc_us-gaap_MajorCustomersAxis to loc_us-gaap_NameOfMajorCustomerDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis to loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MinimumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MinimumMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SalesRevenueServicesNetMember" xlink:label="loc_us-gaap_SalesRevenueServicesNetMember" xlink:title="SalesRevenueServicesNetMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="loc_us-gaap_SalesRevenueServicesNetMember" xlink:title="Definition : loc_us-gaap_ConcentrationRiskBenchmarkDomain to loc_us-gaap_SalesRevenueServicesNetMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember" xlink:title="CustomerConcentrationRiskMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTypeDomain to loc_us-gaap_CustomerConcentrationRiskMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_TopFiveCustomersMember" xlink:label="loc_sncr_TopFiveCustomersMember" xlink:title="TopFiveCustomersMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain" xlink:to="loc_sncr_TopFiveCustomersMember" xlink:title="Definition : loc_us-gaap_NameOfMajorCustomerDomain to loc_sncr_TopFiveCustomersMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="loc_us-gaap_SoftwareDevelopmentMember" xlink:title="SoftwareDevelopmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_SoftwareDevelopmentMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_SoftwareDevelopmentMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesAbstract" xlink:label="loc_us-gaap_MarketableSecuritiesAbstract" xlink:title="MarketableSecuritiesAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" xlink:label="loc_sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" xlink:title="MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesAbstract" xlink:to="loc_sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" xlink:title="Definition : loc_us-gaap_MarketableSecuritiesAbstract to loc_sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_GoodwillAbstract" xlink:label="loc_sncr_GoodwillAbstract" xlink:title="GoodwillAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss" xlink:title="GoodwillImpairmentLoss" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_GoodwillAbstract" xlink:to="loc_us-gaap_GoodwillImpairmentLoss" xlink:title="Definition : loc_sncr_GoodwillAbstract to loc_us-gaap_GoodwillImpairmentLoss" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetImpairmentChargesAbstract" xlink:label="loc_us-gaap_AssetImpairmentChargesAbstract" xlink:title="AssetImpairmentChargesAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:title="ImpairmentOfLongLivedAssetsHeldForUse" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetImpairmentChargesAbstract" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:title="Definition : loc_us-gaap_AssetImpairmentChargesAbstract to loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ResearchAndDevelopmentAbstract" xlink:label="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:title="ResearchAndDevelopmentAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CapitalizedComputerSoftwareUsefulLifeMinimum" xlink:label="loc_sncr_CapitalizedComputerSoftwareUsefulLifeMinimum" xlink:title="CapitalizedComputerSoftwareUsefulLifeMinimum" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:to="loc_sncr_CapitalizedComputerSoftwareUsefulLifeMinimum" xlink:title="Definition : loc_us-gaap_ResearchAndDevelopmentAbstract to loc_sncr_CapitalizedComputerSoftwareUsefulLifeMinimum" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:title="PropertyPlantAndEquipmentAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:title="PropertyPlantAndEquipmentUsefulLife" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentAbstract to loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTable to loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember_1" xlink:title="RangeMember_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis" xlink:to="RangeMember_1" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="ConcentrationRiskBenchmarkDomain_2" xlink:title="ConcentrationRiskBenchmarkDomain_2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="ConcentrationRiskBenchmarkDomain_2" xlink:title="Definition : loc_us-gaap_ConcentrationRiskByBenchmarkAxis to loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="ConcentrationRiskTypeDomain_3" xlink:title="ConcentrationRiskTypeDomain_3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:to="ConcentrationRiskTypeDomain_3" xlink:title="Definition : loc_us-gaap_ConcentrationRiskByTypeAxis to loc_us-gaap_ConcentrationRiskTypeDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="NameOfMajorCustomerDomain_4" xlink:title="NameOfMajorCustomerDomain_4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MajorCustomersAxis" xlink:to="NameOfMajorCustomerDomain_4" xlink:title="Definition : loc_us-gaap_MajorCustomersAxis to loc_us-gaap_NameOfMajorCustomerDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="loc_us-gaap_AccountsReceivableMember" xlink:title="AccountsReceivableMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="loc_us-gaap_AccountsReceivableMember" xlink:title="Definition : loc_us-gaap_ConcentrationRiskBenchmarkDomain to loc_us-gaap_AccountsReceivableMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ATAndTIncMember" xlink:label="loc_sncr_ATAndTIncMember" xlink:title="ATAndTIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain" xlink:to="loc_sncr_ATAndTIncMember" xlink:title="Definition : loc_us-gaap_NameOfMajorCustomerDomain to loc_sncr_ATAndTIncMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NumberOfTopCustomers" xlink:label="loc_sncr_NumberOfTopCustomers" xlink:title="NumberOfTopCustomers" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_sncr_NumberOfTopCustomers" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_sncr_NumberOfTopCustomers" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MarketableSecuritiesMaturityPeriod" xlink:label="loc_sncr_MarketableSecuritiesMaturityPeriod" xlink:title="MarketableSecuritiesMaturityPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesAbstract" xlink:to="loc_sncr_MarketableSecuritiesMaturityPeriod" xlink:title="Definition : loc_us-gaap_MarketableSecuritiesAbstract to loc_sncr_MarketableSecuritiesMaturityPeriod" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CapitalizedComputerSoftwareUsefulLifeMaximum" xlink:label="loc_sncr_CapitalizedComputerSoftwareUsefulLifeMaximum" xlink:title="CapitalizedComputerSoftwareUsefulLifeMaximum" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:to="loc_sncr_CapitalizedComputerSoftwareUsefulLifeMaximum" xlink:title="Definition : loc_us-gaap_ResearchAndDevelopmentAbstract to loc_sncr_CapitalizedComputerSoftwareUsefulLifeMaximum" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTable to loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_VerizonWirelessMember" xlink:label="loc_sncr_VerizonWirelessMember" xlink:title="VerizonWirelessMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain" xlink:to="loc_sncr_VerizonWirelessMember" xlink:title="Definition : loc_us-gaap_NameOfMajorCustomerDomain to loc_sncr_VerizonWirelessMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1" xlink:title="ConcentrationRiskPercentage1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_ConcentrationRiskPercentage1" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareGross" xlink:title="CapitalizedComputerSoftwareGross" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareGross" xlink:title="Definition : loc_us-gaap_ResearchAndDevelopmentAbstract to loc_us-gaap_CapitalizedComputerSoftwareGross" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="loc_us-gaap_MajorCustomersAxis" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTable to loc_us-gaap_MajorCustomersAxis" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_MarketableSecuritiesAbstract" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_MarketableSecuritiesAbstract" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalizedComputerSoftwareAmortization" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareAmortization" xlink:title="CapitalizedComputerSoftwareAmortization" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareAmortization" xlink:title="Definition : loc_us-gaap_ResearchAndDevelopmentAbstract to loc_us-gaap_CapitalizedComputerSoftwareAmortization" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_sncr_GoodwillAbstract" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_sncr_GoodwillAbstract" xlink:type="arc" use="optional" order="5" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:title="Definition : loc_us-gaap_ConcentrationRiskTable to loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="arc" use="optional" order="5" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_AssetImpairmentChargesAbstract" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_AssetImpairmentChargesAbstract" xlink:type="arc" use="optional" order="6" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_ResearchAndDevelopmentAbstract" xlink:type="arc" use="optional" order="7" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits" xlink:label="loc_sncr_ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits" xlink:title="ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_sncr_ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_sncr_ConcentrationRiskCreditRiskFinancialInstrumentDenominationsForExcessCashDeposits" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ServiceAgreementTermOfAgreement" xlink:label="loc_sncr_ServiceAgreementTermOfAgreement" xlink:title="ServiceAgreementTermOfAgreement" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="loc_sncr_ServiceAgreementTermOfAgreement" xlink:title="Definition : loc_us-gaap_ConcentrationRiskLineItems to loc_sncr_ServiceAgreementTermOfAgreement" xlink:type="arc" use="optional" order="8001" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureStockPlansDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="loc_us-gaap_PlanNameDomain" xlink:title="Definition : loc_us-gaap_PlanNameAxis to loc_us-gaap_PlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="Definition : loc_us-gaap_AwardTypeAxis to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MinimumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MinimumMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2000And2006PlanMember" xlink:label="loc_sncr_StockIncentive2000And2006PlanMember" xlink:title="StockIncentive2000And2006PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2000And2006PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2000And2006PlanMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2000PlanMember" xlink:label="loc_sncr_StockIncentive2000PlanMember" xlink:title="StockIncentive2000PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_StockIncentive2000And2006PlanMember" xlink:to="loc_sncr_StockIncentive2000PlanMember" xlink:title="Definition : loc_sncr_StockIncentive2000And2006PlanMember to loc_sncr_StockIncentive2000PlanMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember" xlink:title="EmployeeStockOptionMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_EmployeeStockOptionMember" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to loc_us-gaap_EmployeeStockOptionMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:title="EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_AwardTypeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_AwardTypeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2010PlanMember" xlink:label="loc_sncr_StockIncentive2010PlanMember" xlink:title="StockIncentive2010PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2010PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2010PlanMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2006PlanMember" xlink:label="loc_sncr_StockIncentive2006PlanMember" xlink:title="StockIncentive2006PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_StockIncentive2000And2006PlanMember" xlink:to="loc_sncr_StockIncentive2006PlanMember" xlink:title="Definition : loc_sncr_StockIncentive2000And2006PlanMember to loc_sncr_StockIncentive2006PlanMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember" xlink:title="RestrictedStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockMember" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to loc_us-gaap_RestrictedStockMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NumberOfStockBasedCompensationPlans" xlink:label="loc_sncr_NumberOfStockBasedCompensationPlans" xlink:title="NumberOfStockBasedCompensationPlans" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_NumberOfStockBasedCompensationPlans" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_NumberOfStockBasedCompensationPlans" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:title="AllocatedShareBasedCompensationExpense" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised" xlink:title="ProceedsFromStockOptionsExercised" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ProceedsFromStockOptionsExercised" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_PlanNameAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_PlanNameAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2013PlanMember" xlink:label="loc_sncr_PerformanceShare2013PlanMember" xlink:title="PerformanceShare2013PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2013PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2013PlanMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardIssuePriceAsPercentageOfGrantDateFairMarketValueMinimum" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardIssuePriceAsPercentageOfGrantDateFairMarketValueMinimum" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardIssuePriceAsPercentageOfGrantDateFairMarketValueMinimum" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardIssuePriceAsPercentageOfGrantDateFairMarketValueMinimum" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardIssuePriceAsPercentageOfGrantDateFairMarketValueMinimum" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:title="AllocatedShareBasedCompensationExpenseNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:title="Definition : loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2012PlanMember" xlink:label="loc_sncr_PerformanceShare2012PlanMember" xlink:title="PerformanceShare2012PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2012PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2012PlanMember" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AllocatedShareBasedCompensationExpensePerDilutedShare" xlink:label="loc_sncr_AllocatedShareBasedCompensationExpensePerDilutedShare" xlink:title="AllocatedShareBasedCompensationExpensePerDilutedShare" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_sncr_AllocatedShareBasedCompensationExpensePerDilutedShare" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_sncr_AllocatedShareBasedCompensationExpensePerDilutedShare" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisableOptionsAsPercentageOfSharesSubjectToVesting" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisableOptionsAsPercentageOfSharesSubjectToVesting" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisableOptionsAsPercentageOfSharesSubjectToVesting" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisableOptionsAsPercentageOfSharesSubjectToVesting" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisableOptionsAsPercentageOfSharesSubjectToVesting" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnFirstAnniversaryOfGrantDate" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnFirstAnniversaryOfGrantDate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnFirstAnniversaryOfGrantDate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnFirstAnniversaryOfGrantDate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnFirstAnniversaryOfGrantDate" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:title="Definition : loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract to loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardMonthlyPortionOfOptionsVestingThereafter" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardMonthlyPortionOfOptionsVestingThereafter" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardMonthlyPortionOfOptionsVestingThereafter" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardMonthlyPortionOfOptionsVestingThereafter" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardMonthlyPortionOfOptionsVestingThereafter" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnSecondAnniversaryOfGrantDate" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnSecondAnniversaryOfGrantDate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnSecondAnniversaryOfGrantDate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnSecondAnniversaryOfGrantDate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOptionsVestingOnSecondAnniversaryOfGrantDate" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:title="DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:title="StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="arc" use="optional" order="11" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:type="arc" use="optional" order="12" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:type="arc" use="optional" order="13" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:type="arc" use="optional" order="14" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:type="arc" use="optional" order="15" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:type="arc" use="optional" order="16" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:type="arc" use="optional" order="17" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:type="arc" use="optional" order="18" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2010PlanMember" xlink:label="loc_sncr_PerformanceShare2010PlanMember" xlink:title="PerformanceShare2010PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2010PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2010PlanMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2011PlanMember" xlink:label="loc_sncr_PerformanceShare2011PlanMember" xlink:title="PerformanceShare2011PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2011PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2011PlanMember" xlink:type="arc" use="optional" order="8001" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureCreditFacilityDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:title="LineOfCreditFacilityLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable" xlink:title="DebtInstrumentTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="loc_us-gaap_DebtInstrumentTable" xlink:title="Definition : loc_us-gaap_LineOfCreditFacilityLineItems to loc_us-gaap_DebtInstrumentTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis" xlink:title="CreditFacilityAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain" xlink:title="CreditFacilityDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis" xlink:to="loc_us-gaap_CreditFacilityDomain" xlink:title="Definition : loc_us-gaap_CreditFacilityAxis to loc_us-gaap_CreditFacilityDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember" xlink:title="LineOfCreditMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain" xlink:to="loc_us-gaap_LineOfCreditMember" xlink:title="Definition : loc_us-gaap_CreditFacilityDomain to loc_us-gaap_LineOfCreditMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable" xlink:to="loc_us-gaap_CreditFacilityAxis" xlink:title="Definition : loc_us-gaap_DebtInstrumentTable to loc_us-gaap_CreditFacilityAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="CreditFacilityDomain_1" xlink:title="CreditFacilityDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis" xlink:to="CreditFacilityDomain_1" xlink:title="Definition : loc_us-gaap_CreditFacilityAxis to loc_us-gaap_CreditFacilityDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:title="LineOfCreditFacilityMaximumBorrowingCapacity" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:title="Definition : loc_us-gaap_LineOfCreditFacilityLineItems to loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" xlink:label="loc_sncr_LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" xlink:title="LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="loc_sncr_LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" xlink:title="Definition : loc_us-gaap_LineOfCreditFacilityLineItems to loc_sncr_LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LineOfCreditFacilityAmountOutstanding" xlink:label="loc_us-gaap_LineOfCreditFacilityAmountOutstanding" xlink:title="LineOfCreditFacilityAmountOutstanding" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="loc_us-gaap_LineOfCreditFacilityAmountOutstanding" xlink:title="Definition : loc_us-gaap_LineOfCreditFacilityLineItems to loc_us-gaap_LineOfCreditFacilityAmountOutstanding" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm" xlink:title="DebtInstrumentTerm" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems" xlink:to="loc_us-gaap_DebtInstrumentTerm" xlink:title="Definition : loc_us-gaap_LineOfCreditFacilityLineItems to loc_us-gaap_DebtInstrumentTerm" xlink:type="arc" use="optional" order="8000" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureAccumulatedOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:title="AccumulatedOtherComprehensiveIncomeLossLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:title="AccumulatedOtherComprehensiveIncomeLossTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:title="Definition : loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems to loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" xlink:title="StatementEquityComponentsAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="loc_us-gaap_EquityComponentDomain" xlink:title="Definition : loc_us-gaap_StatementEquityComponentsAxis to loc_us-gaap_EquityComponentDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember" xlink:title="AccumulatedTranslationAdjustmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_AccumulatedTranslationAdjustmentMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:label="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="Definition : loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward to loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:to="loc_us-gaap_StatementEquityComponentsAxis" xlink:title="Definition : loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable to loc_us-gaap_StatementEquityComponentsAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="EquityComponentDomain_1" xlink:title="EquityComponentDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="EquityComponentDomain_1" xlink:title="Definition : loc_us-gaap_StatementEquityComponentsAxis to loc_us-gaap_EquityComponentDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:title="AccumulatedNetUnrealizedInvestmentGainLossMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:title="Definition : loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems to loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:title="OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:title="Definition : loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward to loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_AccumulatedNetGainLossOnIntraEntityForeignCurrencyTransactionsMember" xlink:label="loc_sncr_AccumulatedNetGainLossOnIntraEntityForeignCurrencyTransactionsMember" xlink:title="AccumulatedNetGainLossOnIntraEntityForeignCurrencyTransactionsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_sncr_AccumulatedNetGainLossOnIntraEntityForeignCurrencyTransactionsMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_sncr_AccumulatedNetGainLossOnIntraEntityForeignCurrencyTransactionsMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:title="Definition : loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward to loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:title="ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:title="Definition : loc_sncr_AccumulatedOtherComprehensiveIncomeLossNetOfTaxRollForward to loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:type="arc" use="optional" order="4" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureRestructuringChargesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems" xlink:title="RestructuringCostAndReserveLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:title="ScheduleOfRestructuringAndRelatedCostsTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:title="Definition : loc_us-gaap_RestructuringCostAndReserveLineItems to loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:title="RestructuringCostAndReserveAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain" xlink:title="TypeOfRestructuringDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:to="loc_us-gaap_TypeOfRestructuringDomain" xlink:title="Definition : loc_us-gaap_RestructuringCostAndReserveAxis to loc_us-gaap_TypeOfRestructuringDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember" xlink:title="EmployeeSeveranceMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain" xlink:to="loc_us-gaap_EmployeeSeveranceMember" xlink:title="Definition : loc_us-gaap_TypeOfRestructuringDomain to loc_us-gaap_EmployeeSeveranceMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringReserveRollForward" xlink:label="loc_us-gaap_RestructuringReserveRollForward" xlink:title="RestructuringReserveRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges" xlink:title="RestructuringCharges" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward" xlink:to="loc_us-gaap_RestructuringCharges" xlink:title="Definition : loc_us-gaap_RestructuringReserveRollForward to loc_us-gaap_RestructuringCharges" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable to loc_us-gaap_RestructuringCostAndReserveAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="TypeOfRestructuringDomain_1" xlink:title="TypeOfRestructuringDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:to="TypeOfRestructuringDomain_1" xlink:title="Definition : loc_us-gaap_RestructuringCostAndReserveAxis to loc_us-gaap_TypeOfRestructuringDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FacilityClosingMember" xlink:label="loc_us-gaap_FacilityClosingMember" xlink:title="FacilityClosingMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain" xlink:to="loc_us-gaap_FacilityClosingMember" xlink:title="Definition : loc_us-gaap_TypeOfRestructuringDomain to loc_us-gaap_FacilityClosingMember" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems" xlink:to="loc_us-gaap_RestructuringReserveRollForward" xlink:title="Definition : loc_us-gaap_RestructuringCostAndReserveLineItems to loc_us-gaap_RestructuringReserveRollForward" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="loc_us-gaap_PaymentsForRestructuring" xlink:title="PaymentsForRestructuring" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward" xlink:to="loc_us-gaap_PaymentsForRestructuring" xlink:title="Definition : loc_us-gaap_RestructuringReserveRollForward to loc_us-gaap_PaymentsForRestructuring" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringReserveAccrualAdjustment" xlink:label="loc_us-gaap_RestructuringReserveAccrualAdjustment" xlink:title="RestructuringReserveAccrualAdjustment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward" xlink:to="loc_us-gaap_RestructuringReserveAccrualAdjustment" xlink:title="Definition : loc_us-gaap_RestructuringReserveRollForward to loc_us-gaap_RestructuringReserveAccrualAdjustment" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve" xlink:title="RestructuringReserve" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward" xlink:to="loc_us-gaap_RestructuringReserve" xlink:title="Definition : loc_us-gaap_RestructuringReserveRollForward to loc_us-gaap_RestructuringReserve" xlink:type="arc" use="optional" order="4" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureBasisOfPresentationDetails">
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BasisOfPresentationLineItems" xlink:label="loc_sncr_BasisOfPresentationLineItems" xlink:title="BasisOfPresentationLineItems" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ScheduleOfBasisOfPresentationTable" xlink:label="loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:title="ScheduleOfBasisOfPresentationTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_sncr_BasisOfPresentationLineItems" xlink:to="loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:title="Definition : loc_sncr_BasisOfPresentationLineItems to loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="Definition : loc_us-gaap_StatementScenarioAxis to loc_us-gaap_ScenarioUnspecifiedDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorCustomersAxis" xlink:label="loc_us-gaap_MajorCustomersAxis" xlink:title="MajorCustomersAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="loc_us-gaap_NameOfMajorCustomerDomain" xlink:title="NameOfMajorCustomerDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MajorCustomersAxis" xlink:to="loc_us-gaap_NameOfMajorCustomerDomain" xlink:title="Definition : loc_us-gaap_MajorCustomersAxis to loc_us-gaap_NameOfMajorCustomerDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestatementAdjustmentMember" xlink:label="loc_us-gaap_RestatementAdjustmentMember" xlink:title="RestatementAdjustmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:to="loc_us-gaap_RestatementAdjustmentMember" xlink:title="Definition : loc_us-gaap_ScenarioUnspecifiedDomain to loc_us-gaap_RestatementAdjustmentMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ATAndTIncMember" xlink:label="loc_sncr_ATAndTIncMember" xlink:title="ATAndTIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain" xlink:to="loc_sncr_ATAndTIncMember" xlink:title="Definition : loc_us-gaap_NameOfMajorCustomerDomain to loc_sncr_ATAndTIncMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_sncr_ScheduleOfBasisOfPresentationTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ServiceAgreementRenewalTerm" xlink:label="loc_sncr_ServiceAgreementRenewalTerm" xlink:title="ServiceAgreementRenewalTerm" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BasisOfPresentationLineItems" xlink:to="loc_sncr_ServiceAgreementRenewalTerm" xlink:title="Definition : loc_sncr_BasisOfPresentationLineItems to loc_sncr_ServiceAgreementRenewalTerm" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:to="loc_us-gaap_StatementScenarioAxis" xlink:title="Definition : loc_sncr_ScheduleOfBasisOfPresentationTable to loc_us-gaap_StatementScenarioAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ServiceAgreementMinimumNoticePeriodForRenewal" xlink:label="loc_sncr_ServiceAgreementMinimumNoticePeriodForRenewal" xlink:title="ServiceAgreementMinimumNoticePeriodForRenewal" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_BasisOfPresentationLineItems" xlink:to="loc_sncr_ServiceAgreementMinimumNoticePeriodForRenewal" xlink:title="Definition : loc_sncr_BasisOfPresentationLineItems to loc_sncr_ServiceAgreementMinimumNoticePeriodForRenewal" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_sncr_ScheduleOfBasisOfPresentationTable" xlink:to="loc_us-gaap_MajorCustomersAxis" xlink:title="Definition : loc_sncr_ScheduleOfBasisOfPresentationTable to loc_us-gaap_MajorCustomersAxis" xlink:type="arc" use="optional" order="3" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureAcquisitionTables">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems" xlink:title="BusinessAcquisitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StrumsoftIncMember" xlink:label="loc_sncr_StrumsoftIncMember" xlink:title="StrumsoftIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_StrumsoftIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_StrumsoftIncMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="BusinessAcquisitionAcquireeDomain_1" xlink:title="BusinessAcquisitionAcquireeDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="BusinessAcquisitionAcquireeDomain_1" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_NewbaySoftwareLimitedMember" xlink:label="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="NewbaySoftwareLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_NewbaySoftwareLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_NewbaySoftwareLimitedMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ScheduleOfBusinessAcquisitionCostOfAcquiredEntityPurchasePriceTableTextBlock" xlink:label="loc_sncr_ScheduleOfBusinessAcquisitionCostOfAcquiredEntityPurchasePriceTableTextBlock" xlink:title="ScheduleOfBusinessAcquisitionCostOfAcquiredEntityPurchasePriceTableTextBlock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_sncr_ScheduleOfBusinessAcquisitionCostOfAcquiredEntityPurchasePriceTableTextBlock" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_sncr_ScheduleOfBusinessAcquisitionCostOfAcquiredEntityPurchasePriceTableTextBlock" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:title="ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:title="ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_OaklandMember" xlink:label="loc_sncr_OaklandMember" xlink:title="OaklandMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_OaklandMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_OaklandMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:title="BusinessAcquisitionProFormaInformationTextBlock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionLineItems to loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpeechCycleIncMember" xlink:label="loc_sncr_SpeechCycleIncMember" xlink:title="SpeechCycleIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpeechCycleIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpeechCycleIncMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="8002" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureSubsequentEventsReviewDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems" xlink:title="SubsequentEventLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable" xlink:title="SubsequentEventTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems" xlink:to="loc_us-gaap_SubsequentEventTable" xlink:title="Definition : loc_us-gaap_SubsequentEventLineItems to loc_us-gaap_SubsequentEventTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MinimumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MinimumMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_SubsequentEventTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ChangeInAnnualEffectiveTaxRateForNextYearDueToEnactmentOfTaxLaw" xlink:label="loc_sncr_ChangeInAnnualEffectiveTaxRateForNextYearDueToEnactmentOfTaxLaw" xlink:title="ChangeInAnnualEffectiveTaxRateForNextYearDueToEnactmentOfTaxLaw" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems" xlink:to="loc_sncr_ChangeInAnnualEffectiveTaxRateForNextYearDueToEnactmentOfTaxLaw" xlink:title="Definition : loc_us-gaap_SubsequentEventLineItems to loc_sncr_ChangeInAnnualEffectiveTaxRateForNextYearDueToEnactmentOfTaxLaw" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="loc_us-gaap_SubsequentEventTypeAxis" xlink:title="Definition : loc_us-gaap_SubsequentEventTable to loc_us-gaap_SubsequentEventTypeAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="loc_us-gaap_StatementScenarioAxis" xlink:title="Definition : loc_us-gaap_SubsequentEventTable to loc_us-gaap_StatementScenarioAxis" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:title="Definition : loc_us-gaap_StatementScenarioAxis to loc_us-gaap_ScenarioUnspecifiedDomain" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="loc_us-gaap_SubsequentEventTypeDomain" xlink:title="Definition : loc_us-gaap_SubsequentEventTypeAxis to loc_us-gaap_SubsequentEventTypeDomain" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember" xlink:title="ScenarioForecastMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain" xlink:to="loc_us-gaap_ScenarioForecastMember" xlink:title="Definition : loc_us-gaap_ScenarioUnspecifiedDomain to loc_us-gaap_ScenarioForecastMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain" xlink:to="loc_us-gaap_SubsequentEventMember" xlink:title="Definition : loc_us-gaap_SubsequentEventTypeDomain to loc_us-gaap_SubsequentEventMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SeparationCosts" xlink:label="loc_sncr_SeparationCosts" xlink:title="SeparationCosts" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems" xlink:to="loc_sncr_SeparationCosts" xlink:title="Definition : loc_us-gaap_SubsequentEventLineItems to loc_sncr_SeparationCosts" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain_1" xlink:title="SubsequentEventTypeDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain_1" xlink:title="Definition : loc_us-gaap_SubsequentEventTypeAxis to loc_us-gaap_SubsequentEventTypeDomain" xlink:type="arc" use="optional" order="8001" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureGoodwillAndIntangiblesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:title="FiniteLivedIntangibleAssetsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:title="ScheduleOfFiniteLivedIntangibleAssetsTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsLineItems to loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis to loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MinimumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MinimumMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember" xlink:title="TradeNamesMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_TradeNamesMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_TradeNamesMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:title="FiniteLivedIntangibleAssetsNetAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:title="FiniteLivedIntangibleAssetsGross" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:title="FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:title="FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable to loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember" xlink:title="DevelopedTechnologyRightsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_DevelopedTechnologyRightsMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:title="FiniteLivedIntangibleAssetUsefulLife" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsLineItems to loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:title="FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CustomerListsAndRelationshipsMember" xlink:label="loc_sncr_CustomerListsAndRelationshipsMember" xlink:title="CustomerListsAndRelationshipsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_sncr_CustomerListsAndRelationshipsMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_sncr_CustomerListsAndRelationshipsMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsTranslationAdjustments" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsTranslationAdjustments" xlink:title="FiniteLivedIntangibleAssetsTranslationAdjustments" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsTranslationAdjustments" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsTranslationAdjustments" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:title="AmortizationOfIntangibleAssets" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsLineItems to loc_us-gaap_AmortizationOfIntangibleAssets" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:title="FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_CapitalizedSoftwareAndPatentsMember" xlink:label="loc_sncr_CapitalizedSoftwareAndPatentsMember" xlink:title="CapitalizedSoftwareAndPatentsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_sncr_CapitalizedSoftwareAndPatentsMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_sncr_CapitalizedSoftwareAndPatentsMember" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:title="IntangibleAssetsNetExcludingGoodwill" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract to loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsLineItems to loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:title="FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember" xlink:title="OrderOrProductionBacklogMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain to loc_us-gaap_OrderOrProductionBacklogMember" xlink:type="arc" use="optional" order="5" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsLineItems to loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:title="FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:title="Definition : loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract to loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:type="arc" use="optional" order="5" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureStockholdersEquityDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="loc_us-gaap_PlanNameDomain" xlink:title="Definition : loc_us-gaap_PlanNameAxis to loc_us-gaap_PlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="Definition : loc_us-gaap_AwardTypeAxis to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember" xlink:title="EmployeeStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_us-gaap_EmployeeStockMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_us-gaap_EmployeeStockMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember" xlink:title="EmployeeStockOptionMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_EmployeeStockOptionMember" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to loc_us-gaap_EmployeeStockOptionMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_AwardTypeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_AwardTypeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="PlanNameDomain_1" xlink:title="PlanNameDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="PlanNameDomain_1" xlink:title="Definition : loc_us-gaap_PlanNameAxis to loc_us-gaap_PlanNameDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember" xlink:title="RestrictedStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockMember" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to loc_us-gaap_RestrictedStockMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_PlanNameAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_PlanNameAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:title="EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" xlink:title="RangeAxis" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_RangeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_RangeAxis" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:label="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis" xlink:to="loc_us-gaap_RangeMember" xlink:title="Definition : loc_us-gaap_RangeAxis to loc_us-gaap_RangeMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MinimumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MinimumMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2000And2006PlanMember" xlink:label="loc_sncr_StockIncentive2000And2006PlanMember" xlink:title="StockIncentive2000And2006PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2000And2006PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2000And2006PlanMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2000PlanMember" xlink:label="loc_sncr_StockIncentive2000PlanMember" xlink:title="StockIncentive2000PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_StockIncentive2000And2006PlanMember" xlink:to="loc_sncr_StockIncentive2000PlanMember" xlink:title="Definition : loc_sncr_StockIncentive2000And2006PlanMember to loc_sncr_StockIncentive2000PlanMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember" xlink:to="loc_us-gaap_MaximumMember" xlink:title="Definition : loc_us-gaap_RangeMember to loc_us-gaap_MaximumMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2010PlanMember" xlink:label="loc_sncr_StockIncentive2010PlanMember" xlink:title="StockIncentive2010PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_StockIncentive2010PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_StockIncentive2010PlanMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StockIncentive2006PlanMember" xlink:label="loc_sncr_StockIncentive2006PlanMember" xlink:title="StockIncentive2006PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_StockIncentive2000And2006PlanMember" xlink:to="loc_sncr_StockIncentive2006PlanMember" xlink:title="Definition : loc_sncr_StockIncentive2000And2006PlanMember to loc_sncr_StockIncentive2006PlanMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2010PlanMember" xlink:label="loc_sncr_PerformanceShare2010PlanMember" xlink:title="PerformanceShare2010PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2010PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2010PlanMember" xlink:type="arc" use="optional" order="8002" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PerformanceShare2011PlanMember" xlink:label="loc_sncr_PerformanceShare2011PlanMember" xlink:title="PerformanceShare2011PlanMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_sncr_PerformanceShare2011PlanMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_sncr_PerformanceShare2011PlanMember" xlink:type="arc" use="optional" order="8003" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureStockPlansDetails4">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="loc_us-gaap_PlanNameDomain" xlink:title="Definition : loc_us-gaap_PlanNameAxis to loc_us-gaap_PlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember" xlink:title="EmployeeStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="loc_us-gaap_EmployeeStockMember" xlink:title="Definition : loc_us-gaap_PlanNameDomain to loc_us-gaap_EmployeeStockMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_TermOfEmployeeStockPurchasePlan" xlink:label="loc_sncr_TermOfEmployeeStockPurchasePlan" xlink:title="TermOfEmployeeStockPurchasePlan" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_sncr_TermOfEmployeeStockPurchasePlan" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_sncr_TermOfEmployeeStockPurchasePlan" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_PlanNameAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_PlanNameAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_EmployeeStockPurchasePlanPayrollWithholdingPeriod" xlink:label="loc_sncr_EmployeeStockPurchasePlanPayrollWithholdingPeriod" xlink:title="EmployeeStockPurchasePlanPayrollWithholdingPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_sncr_EmployeeStockPurchasePlanPayrollWithholdingPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_sncr_EmployeeStockPurchasePlanPayrollWithholdingPeriod" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:title="CommonStockCapitalSharesReservedForFutureIssuance" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PercentageOfFairMarketValueOfCommonStock" xlink:label="loc_sncr_PercentageOfFairMarketValueOfCommonStock" xlink:title="PercentageOfFairMarketValueOfCommonStock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_sncr_PercentageOfFairMarketValueOfCommonStock" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_sncr_PercentageOfFairMarketValueOfCommonStock" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_PercentageMaximumOfTotalCombinedVotingPowerParticipantAllowedToBeGrantedRightToPurchaseCommonStock" xlink:label="loc_sncr_PercentageMaximumOfTotalCombinedVotingPowerParticipantAllowedToBeGrantedRightToPurchaseCommonStock" xlink:title="PercentageMaximumOfTotalCombinedVotingPowerParticipantAllowedToBeGrantedRightToPurchaseCommonStock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_sncr_PercentageMaximumOfTotalCombinedVotingPowerParticipantAllowedToBeGrantedRightToPurchaseCommonStock" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_sncr_PercentageMaximumOfTotalCombinedVotingPowerParticipantAllowedToBeGrantedRightToPurchaseCommonStock" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee" xlink:type="arc" use="optional" order="6" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:title="AllocatedShareBasedCompensationExpenseNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:title="StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:type="arc" use="optional" order="9" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:label="loc_us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:title="ProceedsFromSaleOfTreasuryStock" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:type="arc" use="optional" order="11" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:title="StockRepurchasedDuringPeriodShares" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract to loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:type="arc" use="optional" order="12" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureStockPlansDetails3">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="Definition : loc_us-gaap_AwardTypeAxis to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember" xlink:title="RestrictedStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockMember" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to loc_us-gaap_RestrictedStockMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="loc_us-gaap_AwardTypeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to loc_us-gaap_AwardTypeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1" xlink:title="Definition : loc_us-gaap_AwardTypeAxis to loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="arc" use="optional" order="4" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosurePropertyAndEquipmentDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:title="PropertyPlantAndEquipmentLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentLineItems to loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis to loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember" xlink:title="ComputerEquipmentMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_ComputerEquipmentMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_ComputerEquipmentMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable to loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain_1" xlink:title="PropertyPlantAndEquipmentTypeDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain_1" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis to loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SoftwarePurchasedMember" xlink:label="loc_sncr_SoftwarePurchasedMember" xlink:title="SoftwarePurchasedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_sncr_SoftwarePurchasedMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_sncr_SoftwarePurchasedMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentLineItems to loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConstructionInProgressMember" xlink:label="loc_us-gaap_ConstructionInProgressMember" xlink:title="ConstructionInProgressMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_ConstructionInProgressMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_ConstructionInProgressMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentLineItems to loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember" xlink:title="FurnitureAndFixturesMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_FurnitureAndFixturesMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_FurnitureAndFixturesMember" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentLineItems to loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember" xlink:title="BuildingMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_BuildingMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_BuildingMember" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember" xlink:title="LeaseholdImprovementsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="loc_us-gaap_LeaseholdImprovementsMember" xlink:title="Definition : loc_us-gaap_PropertyPlantAndEquipmentTypeDomain to loc_us-gaap_LeaseholdImprovementsMember" xlink:type="arc" use="optional" order="6" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems" xlink:label="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems" xlink:title="RevenueRecognitionMultipleDeliverableArrangementsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable" xlink:label="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable" xlink:title="RevenueRecognitionMultipleDeliverableArrangementsTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems" xlink:to="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable" xlink:title="Definition : loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems to loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaap_TypeOfArrangementAxis" xlink:title="TypeOfArrangementAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:title="ArrangementsAndNonarrangementTransactionsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:title="Definition : loc_us-gaap_TypeOfArrangementAxis to loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_TransactionAndSubscriptionServiceArrangementsMember" xlink:label="loc_sncr_TransactionAndSubscriptionServiceArrangementsMember" xlink:title="TransactionAndSubscriptionServiceArrangementsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_sncr_TransactionAndSubscriptionServiceArrangementsMember" xlink:title="Definition : loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember to loc_sncr_TransactionAndSubscriptionServiceArrangementsMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable" xlink:to="loc_us-gaap_TypeOfArrangementAxis" xlink:title="Definition : loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsTable to loc_us-gaap_TypeOfArrangementAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="ArrangementsAndNonarrangementTransactionsMember_1" xlink:title="ArrangementsAndNonarrangementTransactionsMember_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis" xlink:to="ArrangementsAndNonarrangementTransactionsMember_1" xlink:title="Definition : loc_us-gaap_TypeOfArrangementAxis to loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ProfessionalServiceAndSoftwareLicenseArrangementsMember" xlink:label="loc_sncr_ProfessionalServiceAndSoftwareLicenseArrangementsMember" xlink:title="ProfessionalServiceAndSoftwareLicenseArrangementsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_sncr_ProfessionalServiceAndSoftwareLicenseArrangementsMember" xlink:title="Definition : loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember to loc_sncr_ProfessionalServiceAndSoftwareLicenseArrangementsMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_RevenueRecognitionMultipleDeliverableArrangementsPercentageOfIndividualArrangementRevenueToNetRevenues" xlink:label="loc_sncr_RevenueRecognitionMultipleDeliverableArrangementsPercentageOfIndividualArrangementRevenueToNetRevenues" xlink:title="RevenueRecognitionMultipleDeliverableArrangementsPercentageOfIndividualArrangementRevenueToNetRevenues" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems" xlink:to="loc_sncr_RevenueRecognitionMultipleDeliverableArrangementsPercentageOfIndividualArrangementRevenueToNetRevenues" xlink:title="Definition : loc_us-gaap_RevenueRecognitionMultipleDeliverableArrangementsLineItems to loc_sncr_RevenueRecognitionMultipleDeliverableArrangementsPercentageOfIndividualArrangementRevenueToNetRevenues" xlink:type="arc" use="optional" order="2" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureStockPlansDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:title="ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems to loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween0.29To11.46Member" xlink:label="loc_sncr_ExercisePriceRangeBetween0.29To11.46Member" xlink:title="ExercisePriceRangeBetween0.29To11.46Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween0.29To11.46Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween0.29To11.46Member" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_1" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:to="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:type="arc" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" xlink:title="SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween11.60To14.00Member" xlink:label="loc_sncr_ExercisePriceRangeBetween11.60To14.00Member" xlink:title="ExercisePriceRangeBetween11.60To14.00Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween11.60To14.00Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween11.60To14.00Member" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:title="SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract to loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:title="SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween15.89To20.91Member" xlink:label="loc_sncr_ExercisePriceRangeBetween15.89To20.91Member" xlink:title="ExercisePriceRangeBetween15.89To20.91Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween15.89To20.91Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween15.89To20.91Member" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:title="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween21.59To27.55Member" xlink:label="loc_sncr_ExercisePriceRangeBetween21.59To27.55Member" xlink:title="ExercisePriceRangeBetween21.59To27.55Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween21.59To27.55Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween21.59To27.55Member" xlink:type="arc" use="optional" order="4" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems to loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween27.92To30.41Member" xlink:label="loc_sncr_ExercisePriceRangeBetween27.92To30.41Member" xlink:title="ExercisePriceRangeBetween27.92To30.41Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween27.92To30.41Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween27.92To30.41Member" xlink:type="arc" use="optional" order="5" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems to loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeBeginningOfPeriodAbstract" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween30.50To30.50Member" xlink:label="loc_sncr_ExercisePriceRangeBetween30.50To30.50Member" xlink:title="ExercisePriceRangeBetween30.50To30.50Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween30.50To30.50Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween30.50To30.50Member" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween30.56To31.02Member" xlink:label="loc_sncr_ExercisePriceRangeBetween30.56To31.02Member" xlink:title="ExercisePriceRangeBetween30.56To31.02Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween30.56To31.02Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween30.56To31.02Member" xlink:type="arc" use="optional" order="7" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween33.82To38.62Member" xlink:label="loc_sncr_ExercisePriceRangeBetween33.82To38.62Member" xlink:title="ExercisePriceRangeBetween33.82To38.62Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween33.82To38.62Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween33.82To38.62Member" xlink:type="arc" use="optional" order="8" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween0.29To9.93Member" xlink:label="loc_sncr_ExercisePriceRangeBetween0.29To9.93Member" xlink:title="ExercisePriceRangeBetween0.29To9.93Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween0.29To9.93Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween0.29To9.93Member" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween10.04To14.00Member" xlink:label="loc_sncr_ExercisePriceRangeBetween10.04To14.00Member" xlink:title="ExercisePriceRangeBetween10.04To14.00Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween10.04To14.00Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween10.04To14.00Member" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween15.89To20.71Member" xlink:label="loc_sncr_ExercisePriceRangeBetween15.89To20.71Member" xlink:title="ExercisePriceRangeBetween15.89To20.71Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween15.89To20.71Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween15.89To20.71Member" xlink:type="arc" use="optional" order="8002" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween20.91To24.46Member" xlink:label="loc_sncr_ExercisePriceRangeBetween20.91To24.46Member" xlink:title="ExercisePriceRangeBetween20.91To24.46Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween20.91To24.46Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween20.91To24.46Member" xlink:type="arc" use="optional" order="8003" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween26.83To27.92Member" xlink:label="loc_sncr_ExercisePriceRangeBetween26.83To27.92Member" xlink:title="ExercisePriceRangeBetween26.83To27.92Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween26.83To27.92Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween26.83To27.92Member" xlink:type="arc" use="optional" order="8004" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween28.46To30.41Member" xlink:label="loc_sncr_ExercisePriceRangeBetween28.46To30.41Member" xlink:title="ExercisePriceRangeBetween28.46To30.41Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween28.46To30.41Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween28.46To30.41Member" xlink:type="arc" use="optional" order="8005" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ExercisePriceRangeBetween31.71To38.62Member" xlink:label="loc_sncr_ExercisePriceRangeBetween31.71To38.62Member" xlink:title="ExercisePriceRangeBetween31.71To38.62Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:to="loc_sncr_ExercisePriceRangeBetween31.71To38.62Member" xlink:title="Definition : loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain to loc_sncr_ExercisePriceRangeBetween31.71To38.62Member" xlink:type="arc" use="optional" order="8006" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureIncomeTaxesDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems" xlink:title="OperatingLossCarryforwardsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable" xlink:title="OperatingLossCarryforwardsTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable" xlink:title="Definition : loc_us-gaap_OperatingLossCarryforwardsLineItems to loc_us-gaap_OperatingLossCarryforwardsTable" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:title="IncomeTaxAuthorityAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:title="IncomeTaxAuthorityDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:title="Definition : loc_us-gaap_IncomeTaxAuthorityAxis to loc_us-gaap_IncomeTaxAuthorityDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InternalRevenueServiceIRSMember" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember" xlink:title="InternalRevenueServiceIRSMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember" xlink:title="Definition : loc_us-gaap_IncomeTaxAuthorityDomain to loc_us-gaap_InternalRevenueServiceIRSMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:title="Definition : loc_us-gaap_OperatingLossCarryforwardsTable to loc_us-gaap_IncomeTaxAuthorityAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="IncomeTaxAuthorityDomain_1" xlink:title="IncomeTaxAuthorityDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:to="IncomeTaxAuthorityDomain_1" xlink:title="Definition : loc_us-gaap_IncomeTaxAuthorityAxis to loc_us-gaap_IncomeTaxAuthorityDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:title="StateAndLocalJurisdictionMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:title="Definition : loc_us-gaap_IncomeTaxAuthorityDomain to loc_us-gaap_StateAndLocalJurisdictionMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaap_OperatingLossCarryforwards" xlink:title="OperatingLossCarryforwards" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="loc_us-gaap_OperatingLossCarryforwards" xlink:title="Definition : loc_us-gaap_OperatingLossCarryforwardsLineItems to loc_us-gaap_OperatingLossCarryforwards" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="loc_us-gaap_ForeignCountryMember" xlink:title="ForeignCountryMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain" xlink:to="loc_us-gaap_ForeignCountryMember" xlink:title="Definition : loc_us-gaap_IncomeTaxAuthorityDomain to loc_us-gaap_ForeignCountryMember" xlink:type="arc" use="optional" order="3" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureValuationAndQualifyingAccountsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:title="ValuationAndQualifyingAccountsDisclosureLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:title="ValuationAndQualifyingAccountsDisclosureTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:title="Definition : loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems to loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:title="ValuationAllowancesAndReservesTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:title="ValuationAllowancesAndReservesDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:title="Definition : loc_us-gaap_ValuationAllowancesAndReservesTypeAxis to loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsMember" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsMember" xlink:title="AllowanceForDoubtfulAccountsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsMember" xlink:title="Definition : loc_us-gaap_ValuationAllowancesAndReservesDomain to loc_us-gaap_AllowanceForDoubtfulAccountsMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:title="MovementInValuationAllowancesAndReservesRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:title="ValuationAllowancesAndReservesChargedToCostAndExpense" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:title="Definition : loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward to loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:title="Definition : loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable to loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="ValuationAllowancesAndReservesDomain_1" xlink:title="ValuationAllowancesAndReservesDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:to="ValuationAllowancesAndReservesDomain_1" xlink:title="Definition : loc_us-gaap_ValuationAllowancesAndReservesTypeAxis to loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:title="ValuationAllowanceOfDeferredTaxAssetsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:title="Definition : loc_us-gaap_ValuationAllowancesAndReservesDomain to loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:title="Definition : loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems to loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:title="ValuationAllowancesAndReservesDeductions" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:title="Definition : loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward to loc_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance" xlink:title="ValuationAllowancesAndReservesBalance" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance" xlink:title="Definition : loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward to loc_us-gaap_ValuationAllowancesAndReservesBalance" xlink:type="arc" use="optional" order="3" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails6">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:title="RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:title="ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:title="Definition : loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems to loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="loc_us-gaap_StatementGeographicalAxis" xlink:title="StatementGeographicalAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain" xlink:title="SegmentGeographicalDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementGeographicalAxis" xlink:to="loc_us-gaap_SegmentGeographicalDomain" xlink:title="Definition : loc_us-gaap_StatementGeographicalAxis to loc_us-gaap_SegmentGeographicalDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/country/2013/country-2013-01-31.xsd#country_US" xlink:label="loc_country_US" xlink:title="US" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain" xlink:to="loc_country_US" xlink:title="Definition : loc_us-gaap_SegmentGeographicalDomain to loc_country_US" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:to="loc_us-gaap_StatementGeographicalAxis" xlink:title="Definition : loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable to loc_us-gaap_StatementGeographicalAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="SegmentGeographicalDomain_1" xlink:title="SegmentGeographicalDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementGeographicalAxis" xlink:to="SegmentGeographicalDomain_1" xlink:title="Definition : loc_us-gaap_StatementGeographicalAxis to loc_us-gaap_SegmentGeographicalDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ForeignMember" xlink:label="loc_sncr_ForeignMember" xlink:title="ForeignMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain" xlink:to="loc_sncr_ForeignMember" xlink:title="Definition : loc_us-gaap_SegmentGeographicalDomain to loc_sncr_ForeignMember" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Revenues" xlink:label="loc_us-gaap_Revenues" xlink:title="Revenues" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:to="loc_us-gaap_Revenues" xlink:title="Definition : loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems to loc_us-gaap_Revenues" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:title="Definition : loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems to loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc" use="optional" order="3" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureLegalMattersDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems" xlink:title="LossContingenciesLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable" xlink:title="LossContingenciesTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems" xlink:to="loc_us-gaap_LossContingenciesTable" xlink:title="Definition : loc_us-gaap_LossContingenciesLineItems to loc_us-gaap_LossContingenciesTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:title="LossContingenciesByNatureOfContingencyAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain" xlink:title="LossContingencyNatureDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:to="loc_us-gaap_LossContingencyNatureDomain" xlink:title="Definition : loc_us-gaap_LossContingenciesByNatureOfContingencyAxis to loc_us-gaap_LossContingencyNatureDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_InfringementOfPatentsMember" xlink:label="loc_sncr_InfringementOfPatentsMember" xlink:title="InfringementOfPatentsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain" xlink:to="loc_sncr_InfringementOfPatentsMember" xlink:title="Definition : loc_us-gaap_LossContingencyNatureDomain to loc_sncr_InfringementOfPatentsMember" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:title="Definition : loc_us-gaap_LossContingenciesTable to loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="LossContingencyNatureDomain_1" xlink:title="LossContingencyNatureDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:to="LossContingencyNatureDomain_1" xlink:title="Definition : loc_us-gaap_LossContingenciesByNatureOfContingencyAxis to loc_us-gaap_LossContingencyNatureDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LossContingencyNumberOfPlaintiffs" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs" xlink:title="LossContingencyNumberOfPlaintiffs" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs" xlink:title="Definition : loc_us-gaap_LossContingenciesLineItems to loc_us-gaap_LossContingencyNumberOfPlaintiffs" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_LossContingenciesTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_InfringementOfPatentNumber" xlink:label="loc_sncr_InfringementOfPatentNumber" xlink:title="InfringementOfPatentNumber" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems" xlink:to="loc_sncr_InfringementOfPatentNumber" xlink:title="Definition : loc_us-gaap_LossContingenciesLineItems to loc_sncr_InfringementOfPatentNumber" xlink:type="arc" use="optional" order="8000" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/DisclosureFairValueMeasurementsOfAssetsAndLiabilitiesDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:title="FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:title="FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:title="Definition : loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems to loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:type="arc" use="optional" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="BusinessAcquisitionAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="BusinessAcquisitionAcquireeDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAxis to loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:title="FairValueByFairValueHierarchyLevelAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:title="Definition : loc_us-gaap_FairValueByFairValueHierarchyLevelAxis to loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis" xlink:title="FairValueByLiabilityClassAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:title="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:title="Definition : loc_us-gaap_FairValueByLiabilityClassAxis to loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpeechCycleIncMember" xlink:label="loc_sncr_SpeechCycleIncMember" xlink:title="SpeechCycleIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpeechCycleIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpeechCycleIncMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" xlink:title="FairValueInputsLevel3Member" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaap_FairValueInputsLevel3Member" xlink:title="Definition : loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain to loc_us-gaap_FairValueInputsLevel3Member" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommitmentsMember" xlink:label="loc_us-gaap_CommitmentsMember" xlink:title="CommitmentsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="loc_us-gaap_CommitmentsMember" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain to loc_us-gaap_CommitmentsMember" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:title="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:title="FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:type="arc" use="optional" order="1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:title="Definition : loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable to loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="arc" use="optional" order="1" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1" xlink:title="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis" xlink:to="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1" xlink:title="Definition : loc_us-gaap_FairValueByLiabilityClassAxis to loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_MiyowaSAMember" xlink:label="loc_sncr_MiyowaSAMember" xlink:title="MiyowaSAMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_MiyowaSAMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_MiyowaSAMember" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:title="Definition : loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems to loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:title="BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="arc" use="optional" order="2" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis" xlink:title="Definition : loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable to loc_us-gaap_FairValueByLiabilityClassAxis" xlink:type="arc" use="optional" order="2" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_StrumsoftIncMember" xlink:label="loc_sncr_StrumsoftIncMember" xlink:title="StrumsoftIncMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_StrumsoftIncMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_StrumsoftIncMember" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustmentForEarnings" xlink:label="loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustmentForEarnings" xlink:title="BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustmentForEarnings" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustmentForEarnings" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustmentForEarnings" xlink:type="arc" use="optional" order="3" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="loc_us-gaap_BusinessAcquisitionAxis" xlink:title="Definition : loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable to loc_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" use="optional" order="3" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:title="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:type="arc" use="optional" order="4" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_ForeignExchangeImpactOfChangeInContingentConsiderationObligation" xlink:label="loc_sncr_ForeignExchangeImpactOfChangeInContingentConsiderationObligation" xlink:title="ForeignExchangeImpactOfChangeInContingentConsiderationObligation" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_sncr_ForeignExchangeImpactOfChangeInContingentConsiderationObligation" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_sncr_ForeignExchangeImpactOfChangeInContingentConsiderationObligation" xlink:type="arc" use="optional" order="5" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustment" xlink:label="loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustment" xlink:title="BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustment" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:to="loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustment" xlink:title="Definition : loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward to loc_sncr_BusinessCombinationContingentConsiderationArrangementsContingentConsiderationLiabilityAdjustment" xlink:type="arc" use="optional" order="6" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_FusionOneIncorporatedMember" xlink:label="loc_sncr_FusionOneIncorporatedMember" xlink:title="FusionOneIncorporatedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_FusionOneIncorporatedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_FusionOneIncorporatedMember" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:label="loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:title="SapienceKnowledgeSystemsIncorporatedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SapienceKnowledgeSystemsIncorporatedMember" xlink:type="arc" use="optional" order="8001" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:label="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="SpatialSystemsNomineesPTYLimitedMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:title="Definition : loc_us-gaap_BusinessAcquisitionAcquireeDomain to loc_sncr_SpatialSystemsNomineesPTYLimitedMember" xlink:type="arc" use="optional" order="8002" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.synchronoss.com/role/StatementOfStockholdersEquity">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems" xlink:to="loc_us-gaap_StatementTable" xlink:title="Definition : loc_us-gaap_StatementLineItems to loc_us-gaap_StatementTable" xlink:type="arc" use="optional" order="10" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" xlink:title="StatementEquityComponentsAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="loc_us-gaap_EquityComponentDomain" xlink:title="Definition : loc_us-gaap_StatementEquityComponentsAxis to loc_us-gaap_EquityComponentDomain" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember" xlink:title="CommonStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_CommonStockMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_CommonStockMember" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="IncreaseDecreaseInStockholdersEquityRollForward" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:title="StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:title="StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:title="Definition : loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures to loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="StockIssuedDuringPeriodValueStockOptionsExercised" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="Definition : loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised to loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:title="StockIssuedDuringPeriodValueAcquisitions" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:title="StockIssuedDuringPeriodSharesAcquisitions" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:title="Definition : loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions to loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_EarnOutSharesValueIssuable" xlink:label="loc_sncr_EarnOutSharesValueIssuable" xlink:title="EarnOutSharesValueIssuable" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_EarnOutSharesSharesIssuable" xlink:label="loc_sncr_EarnOutSharesSharesIssuable" xlink:title="EarnOutSharesSharesIssuable" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_EarnOutSharesValueIssuable" xlink:to="loc_sncr_EarnOutSharesSharesIssuable" xlink:title="Definition : loc_sncr_EarnOutSharesValueIssuable to loc_sncr_EarnOutSharesSharesIssuable" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_IssuanceValueOfEarnOutShares" xlink:label="loc_sncr_IssuanceValueOfEarnOutShares" xlink:title="IssuanceValueOfEarnOutShares" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_IssuanceSharesOfEarnOutShares" xlink:label="loc_sncr_IssuanceSharesOfEarnOutShares" xlink:title="IssuanceSharesOfEarnOutShares" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_sncr_IssuanceValueOfEarnOutShares" xlink:to="loc_sncr_IssuanceSharesOfEarnOutShares" xlink:title="Definition : loc_sncr_IssuanceValueOfEarnOutShares to loc_sncr_IssuanceSharesOfEarnOutShares" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:title="StockRepurchasedDuringPeriodValue" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:title="StockRepurchasedDuringPeriodShares" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:title="Definition : loc_us-gaap_StockRepurchasedDuringPeriodValue to loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:title="StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:title="StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:title="Definition : loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan to loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:title="ComprehensiveIncomeNetOfTaxAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="loc_us-gaap_NetIncomeLoss" xlink:title="Definition : loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract to loc_us-gaap_NetIncomeLoss" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:label="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:title="StockholdersEquityPeriodIncreaseDecrease" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:title="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:title="Definition : loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease to loc_us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:type="arc" use="optional" order="10" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable" xlink:to="loc_us-gaap_StatementEquityComponentsAxis" xlink:title="Definition : loc_us-gaap_StatementTable to loc_us-gaap_StatementEquityComponentsAxis" xlink:type="arc" use="optional" order="10" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember" xlink:title="TreasuryStockMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_TreasuryStockMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_TreasuryStockMember" xlink:type="arc" use="optional" order="20" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="Definition : loc_us-gaap_StatementLineItems to loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:type="arc" use="optional" order="20" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:type="arc" use="optional" order="20" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="Definition : loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract to loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:type="arc" use="optional" order="20" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:title="AdditionalPaidInCapitalMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_AdditionalPaidInCapitalMember" xlink:type="arc" use="optional" order="30" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:type="arc" use="optional" order="30" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:title="Definition : loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract to loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:type="arc" use="optional" order="30" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:title="AccumulatedOtherComprehensiveIncomeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="arc" use="optional" order="40" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:type="arc" use="optional" order="40" />
    <link:loc xlink:type="locator" xlink:href="sncr-20131231.xsd#sncr_OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" xlink:label="loc_sncr_OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="loc_sncr_OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" xlink:title="Definition : loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract to loc_sncr_OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" xlink:type="arc" use="optional" order="40" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember" xlink:title="RetainedEarningsMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_RetainedEarningsMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_RetainedEarningsMember" xlink:type="arc" use="optional" order="50" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition" xlink:title="AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition" xlink:type="arc" use="optional" order="50" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:title="ComprehensiveIncomeNetOfTax" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:title="Definition : loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract to loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="arc" use="optional" order="50" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeMember" xlink:label="loc_us-gaap_ComprehensiveIncomeMember" xlink:title="ComprehensiveIncomeMember" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="loc_us-gaap_ComprehensiveIncomeMember" xlink:title="Definition : loc_us-gaap_EquityComponentDomain to loc_us-gaap_ComprehensiveIncomeMember" xlink:type="arc" use="optional" order="60" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_sncr_EarnOutSharesValueIssuable" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_sncr_EarnOutSharesValueIssuable" xlink:type="arc" use="optional" order="60" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_sncr_IssuanceValueOfEarnOutShares" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_sncr_IssuanceValueOfEarnOutShares" xlink:type="arc" use="optional" order="70" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:type="arc" use="optional" order="80" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:type="arc" use="optional" order="90" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:type="arc" use="optional" order="100" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:title="AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:type="arc" use="optional" order="110" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockholdersEquity" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockholdersEquity" xlink:type="arc" use="optional" order="120" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued" xlink:title="CommonStockSharesIssued" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_CommonStockSharesIssued" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_CommonStockSharesIssued" xlink:type="arc" use="optional" order="130" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:type="arc" use="optional" order="140" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:title="StockIssuedDuringPeriodValueNewIssues" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:title="Definition : loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward to loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:type="arc" use="optional" order="8000" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:title="StockIssuedDuringPeriodSharesNewIssues" />
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:title="Definition : loc_us-gaap_StockIssuedDuringPeriodValueNewIssues to loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="arc" use="optional" order="8000" />
  </link:definitionLink>
</link:linkbase>





