1650s, "demigoddess," from Latin heroine, heroina (plural heroinae) "a female hero, a demigoddess" (such as Medea), from Greek hērōine, fem. of hērōs (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.
"one who finds cause for gladness in the most difficult situations," 1921, a reference to Pollyanna Whittier, child heroine of U.S. novelist Eleanor Hodgman Porter's "Pollyanna" (1913) and "Pollyanna Grows Up" (1915), who was noted for keeping her chin up and finding cause for happiness during disasters.
late 14c., "man-like or heroic woman, woman of extraordinary stature, strength and courage," from Latin virago "female warrior, heroine, amazon," from vir "man" (from PIE root *wi-ro- "man"). Ælfric (c. 1000), following Vulgate, used it in Genesis ii.23 as the name Adam gave to Eve (KJV = woman):
Beo hire nama Uirago, þæt is, fæmne, forðan ðe heo is of hire were genumen.
also cliffhanger, "suspenseful situation," 1950, a transferred use from an earlier meaning "movie serial" (1937), from cliff + hang (v.). In some U.S. continued-next-week silent cinema serials in the "Perils of Pauline" days, the episode often ended with the heroine "hanging over a cliff from a fraying rope through which the villain was sawing with a dull knife, to be saved by Crane Wilbur or Milton Sills" [Collier's magazine, July 6, 1946].
late 14c., rescoue, "act of saving from danger, confinement, enemies, etc., from rescue (v.). The earlier noun or form of the noun in Middle English was rescous (early 14c.), from Old French rescous, verbal noun to rescourre, rescorre.
As an adjective by 1888 (William Booth) "aiming to raise fallen or degraded persons," originally and especially prostitutes but also the intemperate; hence rescue mission, for those in need of spiritual or moral rehabilitation. A rescue opera (by 1935, probably translating a continental phrase) was one in which the hero or heroine is rescued after great tribulations.
type of hat, 1887, American English, from "Fédora," a popular play by Victorien Sardou (1831-1908) that opened 1882, in which the heroine, a Russian princess named Fédora Romanoff, originally was performed by Sarah Bernhardt. During the play, Bernhardt, a notorious cross-dresser, wore a center-creased, soft brimmed hat. Women's-rights activists adopted the fashion. The proper name is Russian fem. of Fedor, from Greek Theodoros, literally "gift of god," from theos "god" (from PIE root *dhes-, forming words for religious concepts) + dōron "gift" (from PIE root *do- "to give").