impactEnglishOxford American Thesaurusimpact noun (stress on the first syllable) 1 car parts were spread by the impact over a wide region: collision, crash, smash, clash, bump, bang, knock, jolt, thump, whack, thwack, slam, smack; contact. 2 no car can withstand the impact of a train: force, full force, shock, brunt, impetus, pressure, weight. 3 the job losses will have a major impact | the impact of agriculture on wildlife: effect, influence, impression, footprint; results, aftermath, consequences, repercussions, ramifications, reverberations; informal payoff.verb (stress on the second syllable) 1 North American a comet impacted the earth sixty million years ago: crash into, smash into, collide with, be in collision with, hit, strike, ram, smack into, slam into, bang into, cannon into, plow into, meet head-on, dash against. 2 high interest rates have impacted on retail spending: affect, influence, have an effect, have an influence, exert influence, make an impression, act, work; strike, hit, touch, change, alter, modify, transform, shape, control, govern, determine, decide, sway, bias.