hero, son of Zeus and Alcmene, c.1200 (originally in reference to the Pillars of Hercules), also Ercules, from Latin Hercles, from Greek Herakles, literally "Glory of Hera;" from Hera, q.v. + kleos "glory, renown" (see Clio). Used figuratively of strength since late 14c. Vocative form Hercule was a common Roman interjection (especially me Hercule!) "assuredly, certainly."