"attack violently," c. 1200, from Old French assalir "attack, assault, assail" (12c., Modern French assaillir), from Vulgar Latin *adsalire "to leap at," from Latin ad "to, toward" (see ad-) + salire "to leap" (see salient (adj.)). Figurative use, of mental states, emotions, etc., is from mid-14c.; meaning "attack with arguments, abuse, criticism, etc." is from c. 1400. Related: Assailed; assailing; assailable.