noun
one who is not orthodox in his beliefs
a heretic in religion
Synonyms: dissenter, dissident, misbeliever, nonconformist, schismatic, schismatist, sectary, separatist
Related Word: apostate, defector, iconoclast, recreant, recusant, renegade; infidel, unbeliever; deviationist, revisionist
Antonyms: orthodox