Synonyms and related words :
Young Turk, apostate, backslider, bolter, breakaway, collaborationist, collaborator, convert, defector, demurrer, denominationalist, deserter, dissenter, dissentient, dissident, divisive, factionist, fifth columnist, heretical, heterodox, misbeliever, mugwump, nonconformist, objector, opinionist, opposition voice, proselyte, protestant, protester, quisling, radical, rebellious, recidivist, recreant, recusant, renegade, renegado, renegate, reversionist, runagate, schismatical, seceder, secessionist, sectarian, sectary, separatist, skeptic, strikebreaker, tergiversant, tergiversator, traitor, turnabout, turncoat, turntail, unconventional, unorthodox