(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.