he·ro / ˈhi(ə)rō/ • n. (pl. -roes) a person, typically a man, who is admired or idealized for courage, outstanding achievements, or noble qualities: a war hero. ∎  the chief male character in a book, play, or movie, who is typically identified with good qualities, and with whom the reader is expected to sympathize. ∎  (in mythology and folklore) a person of superhuman qualities and often semidivine origin, in particular one of those whose exploits and dealings with the gods were the subject of ancient Greek myths and legends. ∎  (also hero sandwich) another term for submarine sandwich.

hero man of superhuman qualities, demigod XIV (rare before XVI); illustrious warrior XVI; man admired for his great deeds and noble qualities XVII; chief man in a poem, play, etc. In earliest use chiefly pl heroes, with sg. heroe (both of 3 sylls.) and heros — L. hērōs, pl. hērōēs — Gr. hērōs, pl. hērōes. The common heroe (XVI–XVIII) was superseded by hero (XVII), with pl. heroes (2 sylls.).
So heroic XVI. — F. or L. — Gr. hēroïkós. heroi-comic(al) XVIII. heroine XVII. — F. or L. — Gr. hērōinē. heroism XVIII. — F.

He·ro ¹ / ˈhi(ə)rō/ Greek Mythol. a priestess of Aphrodite at Sestos on the European shore of the Hellespont, whose lover Leander, a youth of Abydos on the opposite shore, swam the strait nightly to visit her. One stormy night he was drowned, and Hero in grief threw herself into the sea.

Hero in Greek mythology, priestess of Aphrodite at Sestos on the European shore of the Hellespont, whose lover Leander, a youth of Abydos on the opposite shore, swam the strait nightly to visit her. One stormy night he was drowned and Hero in grief threw herself into the sea.