To abandon one's religious faith, political party, or set of principles; to become an apostate.
From apostate plus the verb suffix -ize. The verb form allows speakers to describe the action of renouncing one's beliefs or allegiances.
Historically, to apostatize was often a death sentence—heretics who renounced their faith in Medieval Europe faced execution—yet the word itself comes from Greek meaning 'to stand away,' capturing the core idea of separation from a group.
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