What is the Latin word for apostate?

The usual Latin words for “apostate” are dēfector, apostatō. The right choice depends on the sense; see the distinctions below.

English → Latin

“apostate” in Latin

dēfectora deserter, rebel apostatōto forsake one's religion, apostatize

The English word apostate itself goes back to Latin apostata.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

apostate

defector (Tac.): apostata (Tert., Sedul.: ἀποστάτης): *desertor patriae religionis; *qui patria sacra abju rat (Krebs).

Quick answer

What is the Latin word for apostate?: The usual Latin words for “apostate” are dēfector, apostatō. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.