1. past tense and past participle of apostatise; abandoned one's religious faith, political allegiance, or principles
Usage: British spelling (American: apostatized); formal or religious context

Examples

• He apostatised from the church after decades of membership.
• The scholar apostatised from her earlier political beliefs.
• Many who apostatised during the persecution later returned to their faith.
• She apostatised from the movement when she discovered its true intentions.
• The regime punished those who apostatised from the official ideology.
• He apostatised from Christianity and adopted a different worldview.