gallant (adj.) Look up gallant at Dictionary.com
mid-15c., "showy, finely dressed; gay, merry," from Old French galant "courteous," earlier "amusing, entertaining; lively, bold" (14c.), present participle of galer "rejoice, make merry," which is of uncertain origin. Perhaps from a Latinized verb formed from Frankish *wala- "good, well," from Proto-Germanic *wal- (source also of Old High German wallon "to wander, go on a pilgrimage"), from PIE root *wel- (2) "to wish, will" (see will (v.)), "but the transition of sense offers difficulties that are not fully cleared up" [OED]. Sense of "politely attentive to women" was adopted early 17c. from French. Attempts to distinguish this sense by accent are an 18c. artifice.
gallant (n.) Look up gallant at Dictionary.com
mid-15c., "man of fashion and pleasure," earlier "dissolute man, rake" (early 15c.); from gallant (adj.). As "one who is particularly attentive to women" probably by late 15c.