1. eager, headlong. Impetuous, impulsive both refer to persons who are hasty and precipitate in action, or to actions not preceded by thought. Impetuous suggests eagerness, violence, rashness: impetuous vivacity; impetuous desire; impetuous words. Impulsive emphasizes spontaneity and lack of reflection: an impulsive act of generosity.
late 14c., "hot-tempered, fierce," from Old French impetuos (13c.) and directly from Late Latin impetuosus "impetuous, violent," from Latin impetus "attack" (see impetus). Related: Impetuously; impetuousness.