Synonyms and related words :
abjuratory, apostate, backslider, bolter, breakaway, collaborationist, collaborator, convert, defector, deserter, fifth columnist, mugwump, mugwumpian, mugwumpish, proselyte, quisling, recidivist, recreant, renegade, renegado, renegate, renunciative, renunciatory, repudiative, repudiatory, reversionist, revocatory, runagate, schismatic, seceder, separatist, strikebreaker, tergiversant, tergiversator, traitor, turnabout, turncoat, turntail