1939, "of or pertaining to desire felt for the opposite-sex parent," from Oedipus complex (1910), coined by Freud from Sophocles' play "Oedipus Tyrannus," in which the title character, the Theban hero, answers the Sphinx's riddle and unknowingly kills his father and marries his mother; from Greek Oidipous (see Oedipus). The name was used figuratively in English from 1550s for "one who is clever at guessing riddles," which had adjectival form Oedipean (1620s).