- rough and noisy; noisily jolly or rowdy; clamorous; unrestrained: the sound of boisterous laughter.
- (of waves, weather, wind, etc.) rough and stormy.
- Obsolete. rough and massive.
- noisy and lively; unrestrained or unruly
- (of the wind, sea, etc) turbulent or stormy
late 15c., unexplained alteration of Middle English boistous (c.1300) “rough, coarse (as of food), clumsy, violent,” of unknown origin, perhaps from Anglo-French bustous “rough (road),” which is perhaps from Old French boisteos “curved, lame; uneven, rough” (Modern French boiteux), itself of obscure origin. Another guess traces it via Celtic to Latin bestia. Used of persons from 1560s. Related: Boisterously; boisterousness.