Online Etymology Dictionary

hero (n.2): 1955, the New York City term for a sandwich elsewhere called submarine, grinder, poor boy (New Orleans), or hoagie (Philadelphia); origin unknown, perhaps so called for its great size (from hero (n.1)), or a folk-etymology alteration of Greek gyro as a type of sandwich.
hero (n.1): late 14c., "man of superhuman strength or physical courage," from Old French heroe (14c., Modern French héros), from Latin heros (plural heroes) "hero, demi-god, illustrious man," from Greek heros (plural heroes) "demi-god," a variant singular of which was heroe.

This is of uncertain origin; perhaps originally "defender, protector," and from PIE root *ser- (1) "to watch over, protect" (see observe). Meaning "man who exhibits great bravery" in any course of action is from 1660s in English. Sense of "chief male character in a play, story, etc." first recorded 1690s. Hero-worship is from 1713 in reference to ancient cults and mysteries; of living men by 1830s.

In Homer, of the Greeks before Troy, then a comprehensive term used of warriors generally, also of all free men in the Heroic Age. In classical mythology at least from the time of Hesiod (8c. B.C.E.) "man born from a god and a mortal," especially one who had done service to mankind; with the exception of Heracles limited to local deities and patrons of cities.
heroism (n.): 1717, from French héroisme, from héros (see hero (n.1)).
heroic (adj.): 1540s, "having or displaying the qualities of a hero," shortened from heroical (early 15c., also heroycus) "noble, magnanimous," from Latin heroicus "of a hero, heroic, mythical," from Greek heroikos "of or for a hero, pertaining to heroes," from heros (see hero (n.1)). In some modern uses, "having recourse to extreme measures." The Heroic Age, semi-mythical prehistoric period in Greece, ended with the return of the armies from the fall of Troy. Related: Heroically. Heroic verse (1610s), decasyllabic iambic, is from Italian.
Herodian (adj.): pertaining to Herod, name of rulers in ancient Palestine in Roman times, especially Herod the Great, king of Judea 38-4 B.C.E. The name is Greek, Herodes, from heros "hero" (see hero (n.1)) + patronymic suffix -des.
heroine (n.): 1650s, "demigoddess," from Latin heroine, heroina (plural heroinae) "a female hero, a demigoddess" (such as Medea), from Greek heroine, fem. of heros (see hero (n.1)). Meaning "heroic woman, woman distinguished by exalted courage or noble achievements" is from 1660s. Sense of "principal female character in a drama, poem, etc." is from 1715.
heroin (n.): 1898, from German Heroin, coined 1898 as trademark registered by Friedrich Bayer & Co. for their morphine substitute. According to tradition the word was coined with chemical suffix -ine (2) (German -in) + Greek heros "hero" (see hero (n.1)) because of the euphoric feeling the drug provides, but no evidence for this seems to have been found so far.
A new hypnotic, to which the name of 'heroin' has been given, has been tried in the medical clinic of Professor Gerhardt in Berlin. ["The Lancet," Dec. 3, 1898]
antihero (n.): also anti-hero; 1714, from anti- + hero.
Hera: sister and wife of Zeus, the type of virtuous womanhood, from Greek Hera, literally "protectress," related to heros "hero," originally "defender, protector" (see hero (n.1)).
superhero (n.): 1908 (in a translation of Nietzsche), from super- + hero. Used in 1930 of Tarzan; modern use is from 1960s.
heroics (n.): 1590s, "heroic verse" (see heroic). Meaning "deeds worthy of a hero" attested by 1831.
folklore (n.): "traditional beliefs and customs of the common people," 1846, coined by antiquarian William J. Thoms (1803-1885) as an Anglo-Saxonism (replacing popular antiquities) in imitation of German compounds in Volk- and first published in the "Athenaeum" of Aug. 22, 1846; see folk + lore. Old English folclar meant "homily."

This word revived folk in a modern sense of "of the common people, whose culture is handed down orally," and opened up a flood of compound formations: Folk art (1892), folk-hero (1874), folk-medicine (1877), folk-tale (1850; Old English folctalu meant "genealogy"), folk-song (1847, "a song of the people," translating German Volkslied), folk-singer (1876), folk-dance (1877).
Theseus: legendary hero-king of Athens; the name is of uncertain origin.
heron (n.): "long-necked, long-legged wading bird," c. 1300, from Old French hairon, eron (12c.), earlier hairo (11c., Modern French héron), from Frankish *haigiro or some other Germanic source, from Proto-Germanic *hraigran. Related to Old High German heigaro, Danish hejre "heron," German Reiher, Dutch reiger, Old Norse hegri), perhaps from a common IE root imitative of its cry (compare Old Church Slavonic kriku "cry, scream," Lithuanian kryksti "to shriek," Welsh cregyra "heron," Latin graculus "jackdaw, crow"). Old English cognate hraga did not survive into Middle English. Egret is from the same source.
Kalevala: Finnish epic compilation, first published 1835, from Finnish (Finno-Ugric), literally "place or home of a hero," from kaleva "hero" + -la "place."
Bellerophon: Greek hero, from Latin form of Greek Bellerophontes, probably literally "killer of (the demon) Bellerus," from -phontes "killer of."
Aladdin: name of a hero in stories from the Arabian Nights, from Arabic Ala' al Din, literally "nobility of faith."
Robinson Crusoe: "man without companionship," 1768, from the eponymous hero of Daniel Defoe's fictional shipwreck narrative (1719).
Romeo (n.): "a lover, passionate admirer, seducer of women," 1766, from the name of the hero in Shakespeare's tragedy "Romeo and Juliet" (1590s).
sparagmos (n.): ritual death of a hero in tragedy or myth, 1913, from Greek sparagmos, literally "tearing, rending."
Xerxes: king of Persia who reigned 486-465 B.C.E., Greek Xerxes, from Old Persian Xšayaršan, literally "male (i.e. 'hero') among kings," from Xšaya- "to rule over" (see shah) + aršan "male, man, hero." The Hebrew rendition was Ahashwerosh, Ahashresh.
Timon (n.): "misanthrope," from Timon, name of a misanthrope who lived in Athens during the Peloponnesian War (431-404 B.C.E.), hero of Shakespeare's "Timon of Athens" (c. 1605).
Tristram: masc. proper name, name of a medieval hero, from Welsh Drystan, influenced by French triste "sad" (see trist). The German form is Tristan.
kryptonite (n.): fictional substance in the "Superman" series, where it weakens the otherwise invulnerable hero, 1943; perhaps from elements of krypton (which is a gas) + meteorite.
palooka (n.): "mediocre prizefighter," 1926, of unknown origin, credited to U.S. sportswriter and "Variety" staffer Jack Conway (d.1928). Non-boxing sense of "average person" is from Joe Palooka, hero of Ham Fisher's comic strip.
Parzival: also Parsifal, hero of medieval legends, from Old French Perceval, literally "he who breaks through the valley," from percer "to pierce, break through" (see pierce) + val "valley" (see vale).
ghazi (n.): Muslim warrior fighting the infidels, veteran soldier of Islam, 1735, from Arabic ghazi "warrior, champion, hero," properly participle of ghaza (stem gh-z-w) "he made war."
Diomedes: Greek hero in the Trojan War, literally "advised by Zeus," from Dios, genitive of Zeus (see Zeus) + medos "counsel, plan, device, cunning" (see Medea).
Werther: love-lorn hero of Goethe's "Die Leiden des jungen Werthers" ("The Sorrows of Young Werther"), popular and influential short novel published in 1774. His name was used as a type of morbid sentimentality.
Hawkeye (n.): "inhabitant of Iowa," 1839, said to have been the name of an Indian chief, from hawk (n.) + eye (n.). It also was one of the nicknames of the hero, Natty Bumppo, in Fenimore Cooper's "Leatherstocking" novels (1826).
Achilles: Greek hero of the Trojan War stories, son of Thetis and Peleus, his name is perhaps a compound of akhos "pain, grief" (see awe) + laos "the people, a people" (see lay (adj.)); or else it is from a pre-Greek language.
tam-o'-shanter (n.): c. 1840, type of bonnet formerly worn by Scottish plowmen, from Tam O'Shanter "Tom of Shanter," name of hero in a poem of the same name by Robert Burns, written 1790. The woolen cap became fashionable for ladies c. 1887.
zorro (n.): 1838, "South American fox-wolf," from Spanish zorro, masc. of zorra "fox," from Basque azaria "fox." The comic book hero, a variation on the Robin Hood theme set in old Spanish California, was created 1919 by U.S. writer Johnston McCulley (1883-1958).
Peter Pan (n.): name of boy-hero in J.M. Barrie's play "Peter Pan, or The Boy Who Wouldn't Grow Up" (1904). Used allusively for an immature adult man from 1914 (by G.B. Shaw, in reference to the Kaiser).
cliff-hanger (n.): also cliffhanger, "suspenseful situation," 1937, in reference to U.S. cinema serials, agent noun from cliff + agent noun from hang (v.). In some cases, especially Westerns, the hero or heroine literally was dangling from a cliff at the end of an episode.
batman (n.): "officer's servant," originally military title for "man in charge of a bat-horse and its load," 1755, from bat "pack-saddle" (late 14c.), from Old French bast (Modern French bât), from Late Latin bastum (see baton). Hence also batwoman (1941). The comic book hero dates from 1939.
Leander: youth of Abydos, lover of Hero. He swam nightly across the Hellespont to visit her in Sestos, on the Thracian side, until he drowned. The name is from Greek Leiandros, literally "lion-man," from leon "lion" + aner (genitive andros) "man" (see anthropo-).
Prince Charming: 1837, from French Roi Charmant, name of the hero of Comtesse d'Aulnoy's "L'Oiseau Bleu" (1697). In English he was adopted into native fairy tales including "Sleeping Beauty" and "Cinderella."
As for me, I have always agreed with the fairy books that the moment when Prince Charming arrives is the perfect climax. Everything that goes before in the life of a girl simply leads up to that moment, and everything that comes after dates from it; and while the girl of the twentieth century, sallying forth in search of adventure, may not hope to meet at the next turn a knight in shining armor, or a sighing troubadour, she does hope, if she is normal and has the normal dreams of a girl, to find her hero in some of the men who pass her way. [Temple Bailey, "Adventures in Girlhood," Philadelphia, 1919]
Fauntleroy: in various usages, from the gentle boy hero of Frances Hodgson Burnett's popular novel "Little Lord Fauntleroy" (1885). The family name is recorded from mid-13c., literally "son of the king" (Anglo-French Le Enfant le Roy), from faunt, a Middle English variant of enfaunt (see infant). Middle English also had fauntekin "a little child" (late 14c.).
Faustian (adj.): 1870, in reference to Johann Faust (c. 1485-1541), German wandering astrologer and wizard, who was reputed to have sold his soul to the Devil. Fantastic tales of his life were told as early as the late 16c., and he was the hero of dramas by Marlowe and Goethe. The Latinized form of his name, faustus, means "of favorable omen."
main (adj.): early 13c., "large, bulky, strong," from Old English mægen- "power, strength, force," used in compounds (such as mægensibb "great love," mægenbyrðen "heavy burden;" see main (n.)), probably also from or influenced by Old Norse megenn (adj.) "strong, powerful." Sense of "chief" is c. 1400. Main course in the meal sense attested from 1829. Main man "favorite male friend; hero" is from 1967, African-American vernacular.
Nashville: capital of Tennessee, U.S., named for Gen. Francis Nash (1742-1777) of North Carolina, U.S. Revolutionary War hero killed at the Battle of Germantown. The surname is attested from 1296 in Sussex Subsidy Rolls, atten Eysse, atte Nasche (with assimilation of -n- from a preposition; see N), meaning "near an ash tree," or "near a place called Ash." In reference to a type of country & western music that originated there, 1963.
Oedipal (adj.): 1939, "of or pertaining to desire felt for 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 own mother; from Greek Oedipus. The name was used figuratively in English from 1550s for "one who is clever at guessing riddles," which had adjectival form Oedipean (1620s).
valerian (n.): plant of Eurasia, cultivated for its medicinal root, late 14c., from Old French valeriane "wild valerian" (13c.), apparently from feminine singular of Latin adjective Valerianus, from the personal name Valerius (see Valerie); but Weekley writes, "some of the German and Scand. forms of the name point rather to connection with the saga-hero Wieland."
quixotic (adj.): "extravagantly chivalrous," 1791, from Don Quixote, romantic, impractical hero of Cervantes' satirical novel "Don Quixote de la Mancha" (1605; English translation by 1620). His name literally means "thigh," also "a cuisse" (a piece of armor for the thigh), in Modern Spanish quijote, from Latin coxa "hip." Related: Quixotical; quixotically.
Rambo: used allusively from 1985, in reference to John Rambo, hero of David Morrell's novel "First Blood" (1972), popularized as portrayed by Sylvester Stallone in Hollywood movie version (1982), a U.S. Vietnam veteran, "macho and self-sufficient, and bent on violent retribution" [OED]. The family name is an old one in New Jersey and Pennsylvania, originally Swedish, sometimes said to represent Swedish place name Ramberget, or to be from French Huguenots who took refuge in Sweden.
Aeneas: hero of the "Æneid," son of Anchises and Aphrodite, Latin, from Greek Aineias, which is of unknown origin, perhaps literally "praise-worthy," from ainos "tale, story, saying, praise" (related to enigma); or perhaps related to ainos "horrible, terrible." The Aeneid (late 15c. in English) is literally "of or pertaining to Aeneas," from French Enéide, Latin Æneida.
Nestor: name for "old king renowned for wise counsel," 1580s, from Greek, name of the aged and wise hero in the "Iliad," king of Pylus, who outlived three generations. Klein says the name is literally "one who blesses," and is related to nostimos "blessed;" Watkins connects it with the root of the first element in nostalgia.
virile (adj.): late 15c., "characteristic of a man; marked by manly force," from Middle French viril (14c.) and directly from Latin virilis "of a man, manly, worthy of a man," from vir "a man, a hero," from PIE *wi-ro- "man, freeman" (source also of Sanskrit virah, Avestan vira-, Lithuanian vyras, Old Irish fer, Welsh gwr, Gothic wair, Old English wer "man"). Virile member for "penis" is recorded from 1540s.
Hercules: Greek hero, son of Zeus and Alcmene, worshipped by the Romans as a god of strength, c. 1200 (originally in reference to the Pillars of Hercules), also Ercules, from Latin Hercles (Etruscan Hercle), from Greek Herakles, literally "Glory of Hera;" from Hera (q.v.) + kleos "glory, renown" (see Clio). Used figuratively in reference to strength since late 14c. Vocative form Hercule was a common Roman interjection (especially me Hercule!) "assuredly, certainly." The constellation so called in English by 1670s.