Heterodox

From ancient Greek heterodoxos (of another opinion), combining heteros (other, different) and doxa (opinion, belief). The word entered English in the 1630s, originally applied to people holding religious views at variance with official or orthodox positions. Both "heterodox" and "orthodox" share the Greek root doxa, but express opposing concepts: orthodox pairs doxa with orth- (correct, straight), while heterodox pairs it with heter- (other, different)—literally "other opinion" versus "correct opinion."