come-outer

/K AH1 M AW0 T ER0/
noun
  1. 1

    One who abandons or withdraws from an established religion, opinion, custom, creed, etc.

    โ€œDespite her family's wishes, she left Christianity, becoming a come-outer of her former faith.โ€

  2. 2

    One who seeks radical political or religious reform.

Source: https://en.wiktionary.org/wiki/come-outer