(1):
(a.) Contrary to, or differing from, some acknowledged standard, as the Bible, the creed of a church, the decree of a council, and the like; not orthodox; heretical; - said of opinions, doctrines, books, etc., esp. upon theological subjects.
(2):
(a.) Holding heterodox opinions, or doctrines not orthodox; heretical; - said of persons.
(3):
(n.) An opinion opposed to some accepted standard.