also swash-buckler, 1550s, "blustering, swaggering fighting man" (earlier simply swash, 1540s), from swash "fall of a blow" (see swash) + buckler "shield." The original sense seems to have been "one who makes menacing noises by striking his or an opponent's shield."[swashbuckler etymology, swashbuckler origin, 英语词源]