- The definition of an apostasy is the act of leaving behind, or straying from, your religious or political beliefs or your principles.
An example of apostasy is when someone decides to become atheist.
apostasy definition by Webster's New World
Origin: Middle English apostasie ; from Ecclesiastical Late Latin apostasia ; from Classical Greek apo-, away plush stasis, a standing: see stasis
apostasy definition by American Heritage Dictionary
noun pl. a·pos·ta·sies
Origin: Middle English apostasie, from Old French, from Late Latin apostasia, defection, from Late Greek apostasiā, from Greek apostasis, revolt, from aphistanai, aposta-, to revolt : apo-, apo- + histanai, to stand, place; see stā- in Indo-European roots.