<?xml version="1.0" encoding="us-ascii"?>
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:href="sac-20260331.xsd#BasisofPresentationandSummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/FairValueMeasurementsScheduleofGrossHoldingLossGainsandFairValueofHeldtoMaturitySecuritiesDetails" xlink:href="sac-20260331.xsd#FairValueMeasurementsScheduleofGrossHoldingLossGainsandFairValueofHeldtoMaturitySecuritiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/CoverPage" xlink:href="sac-20260331.xsd#CoverPage" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/StatementofChangesinShareholdersDeficitUnaudited" xlink:href="sac-20260331.xsd#StatementofChangesinShareholdersDeficitUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/BalanceSheetsUnaudited" xlink:href="sac-20260331.xsd#BalanceSheetsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/ShareholdersDeficitDetails" xlink:href="sac-20260331.xsd#ShareholdersDeficitDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/RelatedPartyTransactionsDetails" xlink:href="sac-20260331.xsd#RelatedPartyTransactionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/InitialPublicOfferingDetails" xlink:href="sac-20260331.xsd#InitialPublicOfferingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/CommitmentsandContingenciesDetails" xlink:href="sac-20260331.xsd#CommitmentsandContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesDetails" xlink:href="sac-20260331.xsd#BasisofPresentationandSummaryofSignificantAccountingPoliciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/DescriptionofOrganizationandBusinessOperationsDetails" xlink:href="sac-20260331.xsd#DescriptionofOrganizationandBusinessOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/StatementofOperationsUnaudited" xlink:href="sac-20260331.xsd#StatementofOperationsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://safeguardacquisition.com/20260331/role/BalanceSheetsUnauditedParentheticals" xlink:href="sac-20260331.xsd#BalanceSheetsUnauditedParentheticals" xlink:type="simple" />
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesScheduleofBasicandDilutedNetIncomePerOrdinaryShareDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1626" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1627" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1628" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_1633" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicLineItems" xlink:label="us-gaap_EarningsPerShareBasicLineItems_1629" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_1634" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract" xlink:label="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1636" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToParentDiluted" xlink:label="us-gaap_NetIncomeLossAttributableToParentDiluted_1631" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1630" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_1624" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1625" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1635" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1632" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1626_default" />
    <link:definitionArc xlink:type="arc" order="539.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1625" xlink:to="us-gaap_ClassOfStockDomain_1626" />
    <link:definitionArc xlink:type="arc" order="540.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1626" xlink:to="us-gaap_CommonClassAMember_1627" />
    <link:definitionArc xlink:type="arc" order="541.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1626" xlink:to="us-gaap_CommonClassBMember_1628" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" xlink:to="us-gaap_EarningsPerShareBasic_1633" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" xlink:to="us-gaap_EarningsPerShareDiluted_1634" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicLineItems_1629" xlink:to="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1636" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1636" xlink:to="us-gaap_NetIncomeLossAttributableToParentDiluted_1631" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeLossFromContinuingOperationsAttributableToParentAbstract_1636" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_1630" />
    <link:definitionArc xlink:type="arc" order="537.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_EarningsPerShareBasicLineItems_1629" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_1624" />
    <link:definitionArc xlink:type="arc" order="538.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_1624" xlink:to="us-gaap_StatementClassOfStockAxis_1625" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1635" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1632" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicLineItems_1629" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_1637" />
    <link:definitionArc xlink:type="arc" order="539.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1625" xlink:to="us-gaap_ClassOfStockDomain_1626_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/FairValueMeasurementsScheduleofGrossHoldingLossGainsandFairValueofHeldtoMaturitySecuritiesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_USTreasurySecuritiesMatureOn352026Member" xlink:label="sac_USTreasurySecuritiesMatureOn352026Member_1701" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_USTreasurySecuritiesMatureOn642026Member" xlink:label="sac_USTreasurySecuritiesMatureOn642026Member_1700" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_USTreasurySecuritiesMatureOn932026Member" xlink:label="sac_USTreasurySecuritiesMatureOn932026Member_1747" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1676" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_1677" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_1679" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1678" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HeldToMaturitySecurities" xlink:label="us-gaap_HeldToMaturitySecurities_1695" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain" xlink:label="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_1730" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss" xlink:label="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_1758" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HeldToMaturitySecuritiesFairValue" xlink:label="us-gaap_HeldToMaturitySecuritiesFairValue_1697" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1699" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1698" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1678_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1699_default" />
    <link:definitionArc xlink:type="arc" order="597.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1699" xlink:to="sac_USTreasurySecuritiesMatureOn352026Member_1701" />
    <link:definitionArc xlink:type="arc" order="596.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1699" xlink:to="sac_USTreasurySecuritiesMatureOn642026Member_1700" />
    <link:definitionArc xlink:type="arc" order="631.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1699" xlink:to="sac_USTreasurySecuritiesMatureOn932026Member_1747" />
    <link:definitionArc xlink:type="arc" order="573.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1676" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1676" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_1677" />
    <link:definitionArc xlink:type="arc" order="576.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1678" xlink:to="us-gaap_FairValueInputsLevel1Member_1679" />
    <link:definitionArc xlink:type="arc" order="575.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1677" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1678" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" xlink:to="us-gaap_HeldToMaturitySecurities_1695" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" xlink:to="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_1730" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" xlink:to="us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_1758" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_1680" xlink:to="us-gaap_HeldToMaturitySecuritiesFairValue_1697" />
    <link:definitionArc xlink:type="arc" order="595.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1698" xlink:to="us-gaap_RelatedPartyDomain_1699" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_1676" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1698" />
    <link:definitionArc xlink:type="arc" order="575.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_1677" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1678_default" />
    <link:definitionArc xlink:type="arc" order="595.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1698" xlink:to="us-gaap_RelatedPartyDomain_1699_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/CoverPage" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness_1034" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber_1029" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber_1049" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle_1043" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName_1045" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol_1044" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_ClassAOrdinarySharesParValue00001PerShareMember" xlink:label="sac_ClassAOrdinarySharesParValue00001PerShareMember_1009" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnitsEachConsistingOfOneClassAOrdinaryShare00001ParValueAndOnehalfOfOneRedeemableWarrantMember" xlink:label="sac_UnitsEachConsistingOfOneClassAOrdinaryShare00001ParValueAndOnehalfOfOneRedeemableWarrantMember_1008" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_WarrantsEachWholeWarrantExercisableForOneClassAOrdinaryShareAtAnExercisePriceOf1150PerShareMember" xlink:label="sac_WarrantsEachWholeWarrantExercisableForOneClassAOrdinaryShareAtAnExercisePriceOf1150PerShareMember_1010" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag_1021" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode_1048" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate_1030" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus_1024" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus_1023" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems_1011" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable_1003" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate_1022" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport_1537" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport_1019" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType" xlink:label="dei_DocumentType_1012" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1_1037" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2_1038" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown_1039" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode_1042" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince_1040" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey_1026" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding_1060" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus_1031" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany_1035" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod_1036" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber_1027" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory_1033" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode_1028" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent_1020" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName_1025" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany_1032" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1007" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1050" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1051" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1006" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1007_default" />
    <link:definitionArc xlink:type="arc" order="28.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntitySmallBusiness_1034" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityTaxIdentificationNumber_1029" />
    <link:definitionArc xlink:type="arc" order="40.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_LocalPhoneNumber_1049" />
    <link:definitionArc xlink:type="arc" order="36.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_Security12bTitle_1043" />
    <link:definitionArc xlink:type="arc" order="38.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_SecurityExchangeName_1045" />
    <link:definitionArc xlink:type="arc" order="37.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_TradingSymbol_1044" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1007" xlink:to="sac_ClassAOrdinarySharesParValue00001PerShareMember_1009" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1007" xlink:to="sac_UnitsEachConsistingOfOneClassAOrdinaryShare00001ParValueAndOnehalfOfOneRedeemableWarrantMember_1008" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1007" xlink:to="sac_WarrantsEachWholeWarrantExercisableForOneClassAOrdinaryShareAtAnExercisePriceOf1150PerShareMember_1010" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_AmendmentFlag_1021" />
    <link:definitionArc xlink:type="arc" order="39.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_CityAreaCode_1048" />
    <link:definitionArc xlink:type="arc" order="24.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_CurrentFiscalYearEndDate_1030" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentFiscalPeriodFocus_1024" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentFiscalYearFocus_1023" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentInformationTable_1003" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentPeriodEndDate_1022" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentQuarterlyReport_1537" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentTransitionReport_1019" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_DocumentType_1012" />
    <link:definitionArc xlink:type="arc" order="31.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityAddressAddressLine1_1037" />
    <link:definitionArc xlink:type="arc" order="32.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityAddressAddressLine2_1038" />
    <link:definitionArc xlink:type="arc" order="33.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityAddressCityOrTown_1039" />
    <link:definitionArc xlink:type="arc" order="35.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityAddressPostalZipCode_1042" />
    <link:definitionArc xlink:type="arc" order="34.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityAddressStateOrProvince_1040" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityCentralIndexKey_1026" />
    <link:definitionArc xlink:type="arc" order="41.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityCommonStockSharesOutstanding_1060" />
    <link:definitionArc xlink:type="arc" order="25.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityCurrentReportingStatus_1031" />
    <link:definitionArc xlink:type="arc" order="29.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityEmergingGrowthCompany_1035" />
    <link:definitionArc xlink:type="arc" order="30.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityExTransitionPeriod_1036" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityFileNumber_1027" />
    <link:definitionArc xlink:type="arc" order="27.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityFilerCategory_1033" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityIncorporationStateCountryCode_1028" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityInteractiveDataCurrent_1020" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityRegistrantName_1025" />
    <link:definitionArc xlink:type="arc" order="26.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems_1011" xlink:to="dei_EntityShellCompany_1032" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1006" xlink:to="us-gaap_ClassOfStockDomain_1007" />
    <link:definitionArc xlink:type="arc" order="58.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1007" xlink:to="us-gaap_CommonClassAMember_1050" />
    <link:definitionArc xlink:type="arc" order="59.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1007" xlink:to="us-gaap_CommonClassBMember_1051" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dei_DocumentInformationTable_1003" xlink:to="us-gaap_StatementClassOfStockAxis_1006" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1006" xlink:to="us-gaap_ClassOfStockDomain_1007_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/StatementofChangesinShareholdersDeficitUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1072" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_1058" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1062" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_1079" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember_1061" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding" xlink:label="us-gaap_SharesOutstanding_1081" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1069" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_1057" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1074" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1054" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_1080" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_StockIssuedDuringPeriodValueSubsequentRemeasurementOfClassAOrdinarySharesSubjectToRedemption" xlink:label="sac_StockIssuedDuringPeriodValueSubsequentRemeasurementOfClassAOrdinarySharesSubjectToRedemption_1755" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember_1703" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1073" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1071" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_1062_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1073_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1073" xlink:to="us-gaap_CommonClassBMember_1072" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1062" xlink:to="us-gaap_CommonStockMember_1058" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis_1057" xlink:to="us-gaap_EquityComponentDomain_1062" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1074" xlink:to="us-gaap_NetIncomeLoss_1079" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1062" xlink:to="us-gaap_RetainedEarningsMember_1061" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1074" xlink:to="us-gaap_SharesOutstanding_1081" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1054" xlink:to="us-gaap_StatementClassOfStockAxis_1069" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1054" xlink:to="us-gaap_StatementEquityComponentsAxis_1057" />
    <link:definitionArc xlink:type="arc" order="61.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1074" xlink:to="us-gaap_StatementTable_1054" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1074" xlink:to="us-gaap_StockholdersEquity_1080" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1074" xlink:to="sac_StockIssuedDuringPeriodValueSubsequentRemeasurementOfClassAOrdinarySharesSubjectToRedemption_1755" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain_1062" xlink:to="us-gaap_AdditionalPaidInCapitalMember_1703" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1069" xlink:to="us-gaap_ClassOfStockDomain_1073" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1073" xlink:to="us-gaap_CommonClassAMember_1071" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis_1057" xlink:to="us-gaap_EquityComponentDomain_1062_default" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1069" xlink:to="us-gaap_ClassOfStockDomain_1073_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/BalanceSheetsUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_AccruedOfferingCost" xlink:label="sac_AccruedOfferingCost_1488" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_DeferredUnderwritingFeeNonCurrent" xlink:label="sac_DeferredUnderwritingFeeNonCurrent_1558" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PrepaidInsuranceShortTerm" xlink:label="sac_PrepaidInsuranceShortTerm_1737" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent_1192" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_1209" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets_1702" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract_1178" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_1555" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract_1551" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldInTrustNoncurrent" xlink:label="us-gaap_AssetsHeldInTrustNoncurrent_1557" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_1603" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1171" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies_1196" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1173" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1174" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_1208" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_1489" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract_1494" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_1216" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_1194" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract_1187" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue_1207" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1169" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_1215" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract_1199" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_1559" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_1213" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1170" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1176" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent_1553" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent_1556" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1171_default" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract_1187" xlink:to="sac_AccruedOfferingCost_1488" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="sac_DeferredUnderwritingFeeNonCurrent_1558" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract_1551" xlink:to="sac_PrepaidInsuranceShortTerm_1737" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract_1187" xlink:to="us-gaap_AccruedLiabilitiesCurrent_1192" />
    <link:definitionArc xlink:type="arc" order="204.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_AdditionalPaidInCapital_1209" />
    <link:definitionArc xlink:type="arc" order="598.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract_1178" xlink:to="us-gaap_Assets_1702" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1176" xlink:to="us-gaap_AssetsAbstract_1178" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract_1551" xlink:to="us-gaap_AssetsCurrent_1555" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract_1178" xlink:to="us-gaap_AssetsCurrentAbstract_1551" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract_1178" xlink:to="us-gaap_AssetsHeldInTrustNoncurrent_1557" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract_1551" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_1603" />
    <link:definitionArc xlink:type="arc" order="167.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1170" xlink:to="us-gaap_ClassOfStockDomain_1171" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="us-gaap_CommitmentsAndContingencies_1196" />
    <link:definitionArc xlink:type="arc" order="169.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1171" xlink:to="us-gaap_CommonClassAMember_1173" />
    <link:definitionArc xlink:type="arc" order="170.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1171" xlink:to="us-gaap_CommonClassBMember_1174" />
    <link:definitionArc xlink:type="arc" order="203.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_CommonStockValue_1208" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="us-gaap_Liabilities_1489" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="us-gaap_LiabilitiesAbstract_1494" />
    <link:definitionArc xlink:type="arc" order="210.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_1216" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1176" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract_1187" xlink:to="us-gaap_LiabilitiesCurrent_1194" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAbstract_1494" xlink:to="us-gaap_LiabilitiesCurrentAbstract_1187" />
    <link:definitionArc xlink:type="arc" order="202.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_PreferredStockValue_1207" />
    <link:definitionArc xlink:type="arc" order="165.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1176" xlink:to="us-gaap_StatementTable_1169" />
    <link:definitionArc xlink:type="arc" order="209.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_StockholdersEquity_1215" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="us-gaap_StockholdersEquityAbstract_1199" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract_1185" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_1559" />
    <link:definitionArc xlink:type="arc" order="207.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract_1199" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_1213" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1169" xlink:to="us-gaap_StatementClassOfStockAxis_1170" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract_1551" xlink:to="us-gaap_PrepaidExpenseCurrent_1553" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract_1178" xlink:to="us-gaap_PrepaidExpenseNoncurrent_1556" />
    <link:definitionArc xlink:type="arc" order="167.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1170" xlink:to="us-gaap_ClassOfStockDomain_1171_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/ShareholdersDeficitDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember_1279" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_1277" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_TradingDay" xlink:label="sac_TradingDay_1710" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PrivatePlacementWarrantsMember" xlink:label="sac_PrivatePlacementWarrantsMember_1429" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1278" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_DeferredUnderwritersFee" xlink:label="sac_DeferredUnderwritersFee_1642" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_1644" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger" xlink:label="us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_1341" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NewlyAdjustedIssuePricePerShare" xlink:label="sac_NewlyAdjustedIssuePricePerShare_1411" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NumberOfTradingDaysForDeterminingTheNewlyIssuedSharePrice" xlink:label="sac_NumberOfTradingDaysForDeterminingTheNewlyIssuedSharePrice_1416" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1271" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_ShareholdersDeficitTable" xlink:label="sac_ShareholdersDeficitTable_1269" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_1298" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding_1296" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PercentageOfProceedsFromTotalEquity" xlink:label="sac_PercentageOfProceedsFromTotalEquity_1424" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NumberOfTradingDaysForDeterminingTheVolumeWeightedAveragePriceOfShares" xlink:label="sac_NumberOfTradingDaysForDeterminingTheVolumeWeightedAveragePriceOfShares_1425" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_1727" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_1300" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NumberOfConsecutiveTradingDaysForDeterminingTheNewlyIssuedSharePrice" xlink:label="sac_NumberOfConsecutiveTradingDaysForDeterminingTheNewlyIssuedSharePrice_1417" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_ExercisePriceOfWarrantsAsAPercentageOfNewlyIssuedSharePrice" xlink:label="sac_ExercisePriceOfWarrantsAsAPercentageOfNewlyIssuedSharePrice_1427" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized_1293" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1290" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PriorWrittenNoticeOfRedemption" xlink:label="sac_PriorWrittenNoticeOfRedemption_1407" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1272" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_MinimumEffectiveIssuePricePerShare" xlink:label="sac_MinimumEffectiveIssuePricePerShare_1423" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_RedemptionPeriod" xlink:label="sac_RedemptionPeriod_1409" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_1301" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_1302" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_ClassOfWarrantOrRightRedemptionPriceOfWarrants" xlink:label="sac_ClassOfWarrantOrRightRedemptionPriceOfWarrants_1370" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_1728" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_1729" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1270" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1273" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PublicWarrantsMember" xlink:label="sac_PublicWarrantsMember_1281" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1420" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued_1295" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_MinimumPercentageOfVoteForElectionOfDirectors" xlink:label="sac_MinimumPercentageOfVoteForElectionOfDirectors_1336" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1278_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1271_default" />
    <link:definitionArc xlink:type="arc" order="260.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1278" xlink:to="us-gaap_WarrantMember_1279" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_ShareholdersDeficitTable_1269" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_1277" />
    <link:definitionArc xlink:type="arc" order="602.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_TradingDay_1710" />
    <link:definitionArc xlink:type="arc" order="410.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1278" xlink:to="sac_PrivatePlacementWarrantsMember_1429" />
    <link:definitionArc xlink:type="arc" order="259.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1277" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1278" />
    <link:definitionArc xlink:type="arc" order="546.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_DeferredUnderwritersFee_1642" />
    <link:definitionArc xlink:type="arc" order="547.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_1644" />
    <link:definitionArc xlink:type="arc" order="322.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_1341" />
    <link:definitionArc xlink:type="arc" order="392.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_NewlyAdjustedIssuePricePerShare_1411" />
    <link:definitionArc xlink:type="arc" order="397.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_NumberOfTradingDaysForDeterminingTheNewlyIssuedSharePrice_1416" />
    <link:definitionArc xlink:type="arc" order="254.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1270" xlink:to="us-gaap_ClassOfStockDomain_1271" />
    <link:definitionArc xlink:type="arc" order="252.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_ShareholdersDeficitTable_1269" />
    <link:definitionArc xlink:type="arc" order="279.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_CommonStockSharesAuthorized_1298" />
    <link:definitionArc xlink:type="arc" order="277.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_PreferredStockSharesOutstanding_1296" />
    <link:definitionArc xlink:type="arc" order="405.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_PercentageOfProceedsFromTotalEquity_1424" />
    <link:definitionArc xlink:type="arc" order="406.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_NumberOfTradingDaysForDeterminingTheVolumeWeightedAveragePriceOfShares_1425" />
    <link:definitionArc xlink:type="arc" order="603.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_TemporaryEquitySharesOutstanding_1727" />
    <link:definitionArc xlink:type="arc" order="281.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_1300" />
    <link:definitionArc xlink:type="arc" order="398.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_NumberOfConsecutiveTradingDaysForDeterminingTheNewlyIssuedSharePrice_1417" />
    <link:definitionArc xlink:type="arc" order="408.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_ExercisePriceOfWarrantsAsAPercentageOfNewlyIssuedSharePrice_1427" />
    <link:definitionArc xlink:type="arc" order="274.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_PreferredStockSharesAuthorized_1293" />
    <link:definitionArc xlink:type="arc" order="388.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_PriorWrittenNoticeOfRedemption_1407" />
    <link:definitionArc xlink:type="arc" order="255.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1271" xlink:to="us-gaap_CommonClassAMember_1272" />
    <link:definitionArc xlink:type="arc" order="404.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_MinimumEffectiveIssuePricePerShare_1423" />
    <link:definitionArc xlink:type="arc" order="390.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_RedemptionPeriod_1409" />
    <link:definitionArc xlink:type="arc" order="282.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_CommonStockSharesIssued_1301" />
    <link:definitionArc xlink:type="arc" order="283.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_CommonStockSharesOutstanding_1302" />
    <link:definitionArc xlink:type="arc" order="351.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_ClassOfWarrantOrRightRedemptionPriceOfWarrants_1370" />
    <link:definitionArc xlink:type="arc" order="604.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_StockholdersEquity_1728" />
    <link:definitionArc xlink:type="arc" order="615.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding_1729" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_ShareholdersDeficitTable_1269" xlink:to="us-gaap_StatementClassOfStockAxis_1270" />
    <link:definitionArc xlink:type="arc" order="256.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1271" xlink:to="us-gaap_CommonClassBMember_1273" />
    <link:definitionArc xlink:type="arc" order="262.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1278" xlink:to="sac_PublicWarrantsMember_1281" />
    <link:definitionArc xlink:type="arc" order="401.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1420" />
    <link:definitionArc xlink:type="arc" order="276.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="us-gaap_PreferredStockSharesIssued_1295" />
    <link:definitionArc xlink:type="arc" order="317.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1290" xlink:to="sac_MinimumPercentageOfVoteForElectionOfDirectors_1336" />
    <link:definitionArc xlink:type="arc" order="259.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1277" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1278_default" />
    <link:definitionArc xlink:type="arc" order="254.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1270" xlink:to="us-gaap_ClassOfStockDomain_1271_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/RelatedPartyTransactionsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1366" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_1410" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_EngagementFee" xlink:label="sac_EngagementFee_1744" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_ThirdPartyValuationMeasurementInput" xlink:label="sac_ThirdPartyValuationMeasurementInput_1717" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_WorkingCapitalLoans" xlink:label="sac_WorkingCapitalLoans_1441" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NumberOfSharesInAUnit" xlink:label="sac_NumberOfSharesInAUnit_1725" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForFees" xlink:label="us-gaap_PaymentsForFees_1726" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_DirectorMember" xlink:label="srt_DirectorMember_1385" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1264" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1364" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_SponsorMember" xlink:label="sac_SponsorMember_1303" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_SponsorPaid" xlink:label="sac_SponsorPaid_1354" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_1419" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrivatePlacementMember" xlink:label="us-gaap_PrivatePlacementMember_1368" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1310" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="us-gaap_MeasurementInputTypeDomain_1719" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ChiefFinancialOfficerMember" xlink:label="srt_ChiefFinancialOfficerMember_1394" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1292" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1285" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1283" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember" xlink:label="us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember_1720" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputSharePriceMember" xlink:label="us-gaap_MeasurementInputSharePriceMember_1721" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnitsIssuedDuringPeriodShareNewIssues" xlink:label="sac_UnitsIssuedDuringPeriodShareNewIssues_1723" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_AdministrativeSupportAgreementMember" xlink:label="sac_AdministrativeSupportAgreementMember_1297" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_FounderSharesMember" xlink:label="sac_FounderSharesMember_1299" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_MeasurementInputMarketAdjustmentMember" xlink:label="sac_MeasurementInputMarketAdjustmentMember_1722" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1313" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_1400" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense" xlink:label="us-gaap_OtherGeneralAndAdministrativeExpense_1318" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets" xlink:label="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets_1724" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="us-gaap_MeasurementInputTypeAxis_1718" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1365" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems_1304" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_1305" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualAxis" xlink:label="srt_TitleOfIndividualAxis_1383" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1428" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1263" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnderwritersPurchased" xlink:label="sac_UnderwritersPurchased_1431" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PercentageOfPublicShares" xlink:label="sac_PercentageOfPublicShares_1432" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1282" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_RecurringFee" xlink:label="sac_RecurringFee_1745" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PaymentOfServiceFee" xlink:label="sac_PaymentOfServiceFee_1746" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1530" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis_1291" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1264_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="us-gaap_MeasurementInputTypeDomain_1719_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="us-gaap_RelatedPartyTransactionDomain_1292_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1283_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1365_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384_default" />
    <link:definitionArc xlink:type="arc" order="347.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1365" xlink:to="us-gaap_IPOMember_1366" />
    <link:definitionArc xlink:type="arc" order="391.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_1410" />
    <link:definitionArc xlink:type="arc" order="628.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_EngagementFee_1744" />
    <link:definitionArc xlink:type="arc" order="605.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_ThirdPartyValuationMeasurementInput_1717" />
    <link:definitionArc xlink:type="arc" order="420.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_WorkingCapitalLoans_1441" />
    <link:definitionArc xlink:type="arc" order="613.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_NumberOfSharesInAUnit_1725" />
    <link:definitionArc xlink:type="arc" order="614.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_PaymentsForFees_1726" />
    <link:definitionArc xlink:type="arc" order="366.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384" xlink:to="srt_DirectorMember_1385" />
    <link:definitionArc xlink:type="arc" order="249.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1263" xlink:to="us-gaap_RelatedPartyDomain_1264" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1364" />
    <link:definitionArc xlink:type="arc" order="251.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1264" xlink:to="sac_SponsorMember_1303" />
    <link:definitionArc xlink:type="arc" order="335.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_SponsorPaid_1354" />
    <link:definitionArc xlink:type="arc" order="400.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_1419" />
    <link:definitionArc xlink:type="arc" order="349.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1365" xlink:to="us-gaap_PrivatePlacementMember_1368" />
    <link:definitionArc xlink:type="arc" order="291.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_SharesIssuedPricePerShare_1310" />
    <link:definitionArc xlink:type="arc" order="607.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_MeasurementInputTypeAxis_1718" xlink:to="us-gaap_MeasurementInputTypeDomain_1719" />
    <link:definitionArc xlink:type="arc" order="375.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384" xlink:to="srt_ChiefFinancialOfficerMember_1394" />
    <link:definitionArc xlink:type="arc" order="273.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionAxis_1291" xlink:to="us-gaap_RelatedPartyTransactionDomain_1292" />
    <link:definitionArc xlink:type="arc" order="266.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1283" xlink:to="us-gaap_CommonClassBMember_1285" />
    <link:definitionArc xlink:type="arc" order="264.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1282" xlink:to="us-gaap_ClassOfStockDomain_1283" />
    <link:definitionArc xlink:type="arc" order="608.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain_1719" xlink:to="us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember_1720" />
    <link:definitionArc xlink:type="arc" order="609.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain_1719" xlink:to="us-gaap_MeasurementInputSharePriceMember_1721" />
    <link:definitionArc xlink:type="arc" order="611.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_UnitsIssuedDuringPeriodShareNewIssues_1723" />
    <link:definitionArc xlink:type="arc" order="278.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1292" xlink:to="sac_AdministrativeSupportAgreementMember_1297" />
    <link:definitionArc xlink:type="arc" order="280.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain_1292" xlink:to="sac_FounderSharesMember_1299" />
    <link:definitionArc xlink:type="arc" order="610.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain_1719" xlink:to="sac_MeasurementInputMarketAdjustmentMember_1722" />
    <link:definitionArc xlink:type="arc" order="294.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_1313" />
    <link:definitionArc xlink:type="arc" order="381.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_1400" />
    <link:definitionArc xlink:type="arc" order="299.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_OtherGeneralAndAdministrativeExpense_1318" />
    <link:definitionArc xlink:type="arc" order="612.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets_1724" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="us-gaap_MeasurementInputTypeAxis_1718" />
    <link:definitionArc xlink:type="arc" order="346.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1364" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1365" />
    <link:definitionArc xlink:type="arc" order="286.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_1305" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="srt_TitleOfIndividualAxis_1383" />
    <link:definitionArc xlink:type="arc" order="365.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_TitleOfIndividualAxis_1383" xlink:to="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384" />
    <link:definitionArc xlink:type="arc" order="409.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1428" />
    <link:definitionArc xlink:type="arc" order="247.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1263" />
    <link:definitionArc xlink:type="arc" order="412.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_UnderwritersPurchased_1431" />
    <link:definitionArc xlink:type="arc" order="413.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_PercentageOfPublicShares_1432" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="us-gaap_StatementClassOfStockAxis_1282" />
    <link:definitionArc xlink:type="arc" order="629.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_RecurringFee_1745" />
    <link:definitionArc xlink:type="arc" order="630.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems_1304" xlink:to="sac_PaymentOfServiceFee_1746" />
    <link:definitionArc xlink:type="arc" order="475.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1283" xlink:to="us-gaap_CommonClassAMember_1530" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_1262" xlink:to="us-gaap_RelatedPartyTransactionAxis_1291" />
    <link:definitionArc xlink:type="arc" order="249.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1263" xlink:to="us-gaap_RelatedPartyDomain_1264_default" />
    <link:definitionArc xlink:type="arc" order="607.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_MeasurementInputTypeAxis_1718" xlink:to="us-gaap_MeasurementInputTypeDomain_1719_default" />
    <link:definitionArc xlink:type="arc" order="273.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionAxis_1291" xlink:to="us-gaap_RelatedPartyTransactionDomain_1292_default" />
    <link:definitionArc xlink:type="arc" order="264.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1282" xlink:to="us-gaap_ClassOfStockDomain_1283_default" />
    <link:definitionArc xlink:type="arc" order="346.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1364" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1365_default" />
    <link:definitionArc xlink:type="arc" order="365.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_TitleOfIndividualAxis_1383" xlink:to="srt_TitleOfIndividualWithRelationshipToEntityDomain_1384_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/InitialPublicOfferingDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1151" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1160" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1153" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1154" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1152" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1164" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1158" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_InitialPublicOfferingTable" xlink:label="sac_InitialPublicOfferingTable_1150" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_NumberOfSharesInAUnit" xlink:label="sac_NumberOfSharesInAUnit_1166" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnitsIssuedDuringPeriodShareNewIssues" xlink:label="sac_UnitsIssuedDuringPeriodShareNewIssues_1163" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1159" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1162" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1716" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1152_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1159_default" />
    <link:definitionArc xlink:type="arc" order="148.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_InitialPublicOfferingTable_1150" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1151" />
    <link:definitionArc xlink:type="arc" order="157.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1159" xlink:to="us-gaap_CommonClassAMember_1160" />
    <link:definitionArc xlink:type="arc" order="150.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1152" xlink:to="us-gaap_IPOMember_1153" />
    <link:definitionArc xlink:type="arc" order="151.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1152" xlink:to="us-gaap_OverAllotmentOptionMember_1154" />
    <link:definitionArc xlink:type="arc" order="149.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1151" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1152" />
    <link:definitionArc xlink:type="arc" order="160.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1162" xlink:to="us-gaap_SharesIssuedPricePerShare_1164" />
    <link:definitionArc xlink:type="arc" order="155.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_InitialPublicOfferingTable_1150" xlink:to="us-gaap_StatementClassOfStockAxis_1158" />
    <link:definitionArc xlink:type="arc" order="147.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1162" xlink:to="sac_InitialPublicOfferingTable_1150" />
    <link:definitionArc xlink:type="arc" order="162.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1162" xlink:to="sac_NumberOfSharesInAUnit_1166" />
    <link:definitionArc xlink:type="arc" order="159.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1162" xlink:to="sac_UnitsIssuedDuringPeriodShareNewIssues_1163" />
    <link:definitionArc xlink:type="arc" order="156.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1158" xlink:to="us-gaap_ClassOfStockDomain_1159" />
    <link:definitionArc xlink:type="arc" order="604.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1162" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1716" />
    <link:definitionArc xlink:type="arc" order="149.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1151" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1152_default" />
    <link:definitionArc xlink:type="arc" order="156.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1158" xlink:to="us-gaap_ClassOfStockDomain_1159_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTable" xlink:label="sac_BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTable_1180" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldInTrustNoncurrent" xlink:label="us-gaap_AssetsHeldInTrustNoncurrent_1602" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash" xlink:label="us-gaap_Cash_1529" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashEquivalentsAtCarryingValue_1605" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount_1172" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateLineItems" xlink:label="us-gaap_ChangeInAccountingEstimateLineItems_1191" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_1610" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_1607" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1608" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_1606" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember_1609" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits_1756" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1757" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1608_default" />
    <link:definitionArc xlink:type="arc" order="176.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="sac_BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTable_1180" />
    <link:definitionArc xlink:type="arc" order="519.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_AssetsHeldInTrustNoncurrent_1602" />
    <link:definitionArc xlink:type="arc" order="474.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_Cash_1529" />
    <link:definitionArc xlink:type="arc" order="521.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_CashEquivalentsAtCarryingValue_1605" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_CashFDICInsuredAmount_1172" />
    <link:definitionArc xlink:type="arc" order="526.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_1610" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTable_1180" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_1607" />
    <link:definitionArc xlink:type="arc" order="524.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1607" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1608" />
    <link:definitionArc xlink:type="arc" order="522.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_1606" />
    <link:definitionArc xlink:type="arc" order="525.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1608" xlink:to="us-gaap_WarrantMember_1609" />
    <link:definitionArc xlink:type="arc" order="632.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_UnrecognizedTaxBenefits_1756" />
    <link:definitionArc xlink:type="arc" order="633.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ChangeInAccountingEstimateLineItems_1191" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_1757" />
    <link:definitionArc xlink:type="arc" order="524.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1607" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1608_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/BalanceSheetsUnauditedParentheticals" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1230" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1229" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_1707" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_1709" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1235" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1232" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_1241" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_1242" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_1243" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_1236" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1231" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1234" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_1240" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TemporaryEquityRedemptionPricePerShare" xlink:label="us-gaap_TemporaryEquityRedemptionPricePerShare_1708" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized_1237" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued_1238" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding_1239" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1231_default" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1229" xlink:to="us-gaap_StatementClassOfStockAxis_1230" />
    <link:definitionArc xlink:type="arc" order="220.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_StatementTable_1229" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare_1707" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_TemporaryEquitySharesOutstanding_1709" />
    <link:definitionArc xlink:type="arc" order="223.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1231" xlink:to="us-gaap_CommonClassAMember_1232" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_CommonStockSharesAuthorized_1241" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_CommonStockSharesIssued_1242" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_CommonStockSharesOutstanding_1243" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_1236" />
    <link:definitionArc xlink:type="arc" order="222.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1230" xlink:to="us-gaap_ClassOfStockDomain_1231" />
    <link:definitionArc xlink:type="arc" order="225.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1231" xlink:to="us-gaap_CommonClassBMember_1234" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_1240" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_TemporaryEquityRedemptionPricePerShare_1708" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_PreferredStockSharesAuthorized_1237" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_PreferredStockSharesIssued_1238" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1235" xlink:to="us-gaap_PreferredStockSharesOutstanding_1239" />
    <link:definitionArc xlink:type="arc" order="222.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1230" xlink:to="us-gaap_ClassOfStockDomain_1231_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/CommitmentsandContingenciesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems_1340" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnderwritersOptionPeriodFromTheDateOfInitialPublicOffering" xlink:label="sac_UnderwritersOptionPeriodFromTheDateOfInitialPublicOffering_1375" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1376" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnderwrittingAgreementMember" xlink:label="sac_UnderwrittingAgreementMember_1363" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1352" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1351" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis_1360" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare_1390" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnderwritingDiscountPerPublicUnit" xlink:label="sac_UnderwritingDiscountPerPublicUnit_1395" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnitsIssuedDuringPeriodUnitsIssued" xlink:label="sac_UnitsIssuedDuringPeriodUnitsIssued_1347" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_AggregateOfUnderwritingDiscount" xlink:label="sac_AggregateOfUnderwritingDiscount_1638" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_DeferredUnderwritingCommissions" xlink:label="sac_DeferredUnderwritingCommissions_1421" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1361" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_CommitmentsAndContingenciesTable" xlink:label="sac_CommitmentsAndContingenciesTable_1339" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1350" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1351_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1361_default" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_UnderwritersOptionPeriodFromTheDateOfInitialPublicOffering_1375" />
    <link:definitionArc xlink:type="arc" order="357.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1351" xlink:to="us-gaap_IPOMember_1376" />
    <link:definitionArc xlink:type="arc" order="344.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1361" xlink:to="sac_UnderwrittingAgreementMember_1363" />
    <link:definitionArc xlink:type="arc" order="333.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1351" xlink:to="us-gaap_OverAllotmentOptionMember_1352" />
    <link:definitionArc xlink:type="arc" order="332.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1350" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1351" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_CommitmentsAndContingenciesTable_1339" xlink:to="us-gaap_TypeOfArrangementAxis_1360" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="us-gaap_SaleOfStockPricePerShare_1390" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_UnderwritingDiscountPerPublicUnit_1395" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_UnitsIssuedDuringPeriodUnitsIssued_1347" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_AggregateOfUnderwritingDiscount_1638" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_DeferredUnderwritingCommissions_1421" />
    <link:definitionArc xlink:type="arc" order="342.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis_1360" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1361" />
    <link:definitionArc xlink:type="arc" order="320.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_OtherCommitmentsLineItems_1340" xlink:to="sac_CommitmentsAndContingenciesTable_1339" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sac_CommitmentsAndContingenciesTable_1339" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1350" />
    <link:definitionArc xlink:type="arc" order="332.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1350" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1351_default" />
    <link:definitionArc xlink:type="arc" order="342.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis_1360" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_1361_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/DescriptionofOrganizationandBusinessOperationsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PercentageOfFairMarketValue" xlink:label="sac_PercentageOfFairMarketValue_1346" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1714" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnitsIssuedDuringPeriodShareNewIssues" xlink:label="sac_UnitsIssuedDuringPeriodShareNewIssues_1534" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PublicSharePrice" xlink:label="sac_PublicSharePrice_1356" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_SponsorMember" xlink:label="sac_SponsorMember_1408" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PercentageOfRedeemPublicShares" xlink:label="sac_PercentageOfRedeemPublicShares_1371" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1321" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember_1322" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_TrustAccountMember" xlink:label="sac_TrustAccountMember_1362" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1393" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_RedemptionLimitPercentageWithoutPriorConsent" xlink:label="sac_RedemptionLimitPercentageWithoutPriorConsent_1369" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PrivatePlacementUnitsMember" xlink:label="sac_PrivatePlacementUnitsMember_1397" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems_1334" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_TransactionCosts" xlink:label="sac_TransactionCosts_1342" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PublicWarrantsMember" xlink:label="sac_PublicWarrantsMember_1527" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_1526" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_1348" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UsGovernmentSecuritiesMaturityDays" xlink:label="sac_UsGovernmentSecuritiesMaturityDays_1357" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_LiquidationAndDissolutionExpenses" xlink:label="sac_LiquidationAndDissolutionExpenses_1372" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_DeferredUnderwritingFeeNonCurrent" xlink:label="sac_DeferredUnderwritingFeeNonCurrent_1344" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1338" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PricePerPublicShare" xlink:label="sac_PricePerPublicShare_1374" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare_1337" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PrivatePlacementWarrantsMember" xlink:label="sac_PrivatePlacementWarrantsMember_1497" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_PostTransactionCompanyMember" xlink:label="sac_PostTransactionCompanyMember_1414" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1359" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1398" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1396" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1358" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1392" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees" xlink:label="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees_1484" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OverAllotmentOptionMember" xlink:label="us-gaap_OverAllotmentOptionMember_1323" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForUnderwritingExpense" xlink:label="us-gaap_PaymentsForUnderwritingExpense_1343" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseOfferingCost" xlink:label="us-gaap_NoninterestExpenseOfferingCost_1345" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_1495" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1496" />
    <link:loc xlink:type="locator" xlink:href="sac-20260331.xsd#sac_UnderwritersPurchasedOfShares" xlink:label="sac_UnderwritersPurchasedOfShares_1403" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1413" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_1412" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets" xlink:label="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets_1401" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1391" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_1320" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_1321_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_1359_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1392_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_1496_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_1413_default" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_PercentageOfFairMarketValue_1346" />
    <link:definitionArc xlink:type="arc" order="603.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1714" />
    <link:definitionArc xlink:type="arc" order="33.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_UnitsIssuedDuringPeriodShareNewIssues_1534" />
    <link:definitionArc xlink:type="arc" order="20.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_PublicSharePrice_1356" />
    <link:definitionArc xlink:type="arc" order="389.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1359" xlink:to="sac_SponsorMember_1408" />
    <link:definitionArc xlink:type="arc" order="23.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_PercentageOfRedeemPublicShares_1371" />
    <link:definitionArc xlink:type="arc" order="302.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1320" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1321" />
    <link:definitionArc xlink:type="arc" order="303.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1321" xlink:to="us-gaap_IPOMember_1322" />
    <link:definitionArc xlink:type="arc" order="343.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain_1359" xlink:to="sac_TrustAccountMember_1362" />
    <link:definitionArc xlink:type="arc" order="374.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1392" xlink:to="us-gaap_CommonClassAMember_1393" />
    <link:definitionArc xlink:type="arc" order="22.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_RedemptionLimitPercentageWithoutPriorConsent_1369" />
    <link:definitionArc xlink:type="arc" order="378.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1321" xlink:to="sac_PrivatePlacementUnitsMember_1397" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_TransactionCosts_1342" />
    <link:definitionArc xlink:type="arc" order="459.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1496" xlink:to="sac_PublicWarrantsMember_1527" />
    <link:definitionArc xlink:type="arc" order="32.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight_1526" />
    <link:definitionArc xlink:type="arc" order="19.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_1348" />
    <link:definitionArc xlink:type="arc" order="21.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_UsGovernmentSecuritiesMaturityDays_1357" />
    <link:definitionArc xlink:type="arc" order="24.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_LiquidationAndDissolutionExpenses_1372" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_DeferredUnderwritingFeeNonCurrent_1344" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_1338" />
    <link:definitionArc xlink:type="arc" order="25.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_PricePerPublicShare_1374" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_SharesIssuedPricePerShare_1337" />
    <link:definitionArc xlink:type="arc" order="458.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain_1496" xlink:to="sac_PrivatePlacementWarrantsMember_1497" />
    <link:definitionArc xlink:type="arc" order="395.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_1413" xlink:to="sac_PostTransactionCompanyMember_1414" />
    <link:definitionArc xlink:type="arc" order="340.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1358" xlink:to="us-gaap_RelatedPartyDomain_1359" />
    <link:definitionArc xlink:type="arc" order="28.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_1398" />
    <link:definitionArc xlink:type="arc" order="27.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1396" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1358" />
    <link:definitionArc xlink:type="arc" order="373.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1391" xlink:to="us-gaap_ClassOfStockDomain_1392" />
    <link:definitionArc xlink:type="arc" order="31.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ClassOfWarrantOrRightReasonForIssuingToNonemployees_1484" />
    <link:definitionArc xlink:type="arc" order="304.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain_1321" xlink:to="us-gaap_OverAllotmentOptionMember_1323" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_PaymentsForUnderwritingExpense_1343" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_NoninterestExpenseOfferingCost_1345" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_1495" />
    <link:definitionArc xlink:type="arc" order="457.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1495" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1496" />
    <link:definitionArc xlink:type="arc" order="30.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="sac_UnderwritersPurchasedOfShares_1403" />
    <link:definitionArc xlink:type="arc" order="394.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis_1412" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1413" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" xlink:to="us-gaap_BusinessAcquisitionAxis_1412" />
    <link:definitionArc xlink:type="arc" order="29.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets_1401" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" xlink:to="us-gaap_StatementClassOfStockAxis_1391" />
    <link:definitionArc xlink:type="arc" order="293.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems_1334" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_1312" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_1320" />
    <link:definitionArc xlink:type="arc" order="302.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis_1320" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_1321_default" />
    <link:definitionArc xlink:type="arc" order="340.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_1358" xlink:to="us-gaap_RelatedPartyDomain_1359_default" />
    <link:definitionArc xlink:type="arc" order="373.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1391" xlink:to="us-gaap_ClassOfStockDomain_1392_default" />
    <link:definitionArc xlink:type="arc" order="457.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ClassOfWarrantOrRightAxis_1495" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_1496_default" />
    <link:definitionArc xlink:type="arc" order="394.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis_1412" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_1413_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://safeguardacquisition.com/20260331/role/StatementofOperationsUnaudited" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1566" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember_1567" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember_1568" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_1068" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_1070" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_1063" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="us-gaap_InvestmentIncomeInterest_1561" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_1065" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_1569" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_1064" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncome" xlink:label="us-gaap_OtherNonoperatingIncome_1562" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis_1565" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_1563" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_1564" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1570" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1066" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_1566_default" />
    <link:definitionArc xlink:type="arc" order="496.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis_1565" xlink:to="us-gaap_ClassOfStockDomain_1566" />
    <link:definitionArc xlink:type="arc" order="497.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1566" xlink:to="us-gaap_CommonClassAMember_1567" />
    <link:definitionArc xlink:type="arc" order="498.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain_1566" xlink:to="us-gaap_CommonClassBMember_1568" />
    <link:definitionArc xlink:type="arc" order="16.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_EarningsPerShareBasic_1068" />
    <link:definitionArc xlink:type="arc" order="18.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_EarningsPerShareDiluted_1070" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_GeneralAndAdministrativeExpense_1063" />
    <link:definitionArc xlink:type="arc" order="10.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_1569" xlink:to="us-gaap_InvestmentIncomeInterest_1561" />
    <link:definitionArc xlink:type="arc" order="14.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_NetIncomeLoss_1065" />
    <link:definitionArc xlink:type="arc" order="13.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_1569" />
    <link:definitionArc xlink:type="arc" order="12.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_OperatingIncomeLoss_1064" />
    <link:definitionArc xlink:type="arc" order="11.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract_1569" xlink:to="us-gaap_OtherNonoperatingIncome_1562" />
    <link:definitionArc xlink:type="arc" order="495.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable_1564" xlink:to="us-gaap_StatementClassOfStockAxis_1565" />
    <link:definitionArc xlink:type="arc" order="494.00" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_StatementTable_1564" />
    <link:definitionArc xlink:type="arc" order="17.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1570" />
    <link:definitionArc xlink:type="arc" order="15.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems_1563" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_1066" />
    <link:definitionArc xlink:type="arc" order="496.00" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis_1565" xlink:to="us-gaap_ClassOfStockDomain_1566_default" />
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1" xlink:type="simple" />
  <link:definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ChiefExecutiveOfficerMember" xlink:label="us-gaap_ChiefExecutiveOfficerMember" />
    <link:definitionArc xlink:type="arc" order="0" priority="1" xbrldt:closed="true" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="us-gaap_ChiefExecutiveOfficerMember" />
  </link:definitionLink>
</link:linkbase>
