(1):
(n.) Consonance to genuine Scriptural doctrines; - said of moral doctrines and beliefs; as, the orthodoxy of a creed.
(2):
(n.) Soundness of faith; a belief in the doctrines taught in the Scriptures, or in some established standard of faith; - opposed to heterodoxy or to heresy.
(3):
(n.) By extension, said of any correct doctrine or belief.