actuated or swayed by emotional or involuntary impulses

an impulsive child.

having the power or effect of impelling; characterized by impulsion

impulsive forces.

inciting to action

the impulsive effects of a revolutionary idea.

Mechanics . (of forces) acting momentarily; not continuous.

adjective

cautious , considering , heedful , premeditative , thoughtful , wise

adjective

abrupt , ad-lib * , automatic , careless , devil-may-care * , emotional , extemporaneous , flaky * , gone off deep end , hasty , headlong , hot-and-cold , impetuous , instinctive , intuitive , involuntary , jumping the gun , mad , offhand , passionate , precipitate , quick , rash , spontaneous , sudden , swift , unconsidered , unexpected , unmeditated , unpredictable , unpremeditated , unprompted , up-and-down * , violent , winging itnotes:a compulsive eater is compelled by an exterior force to eat and eats constantly; an impulsive eater is impelled (has an impulse) to eat , occurring sporadically , and eats only from time to time , brash , foolhardy , harum-scarum , hotheaded , ill-considered , improvident , incautious , madcap , precipitant , reckless , slapdash , temerarious , reflex , capricious , forceful , impellent , impromptu , propulsive