Do you know ghouls from goblins and ghosts?
Old English unfægr "unlovely," from un- (1) "not" + fair. Cf. Old Norse ufagr, Gothic unfagrs. Meaning "wicked, evil, bad" is recorded from c.1300. Sense of "not equitable, unjust" is first recorded 1713. Related: Unfairly; unfairness.