- The striking of one body against another; collision.
- The force or energy of a collision of two objects.
- The hatchet cut the wood on impact.
- (chiefly medicine) A forced impinging.
- His spine had an impingement; L4 and L5 made impact, which caused numbness in his leg.
- A significant or strong influence; an effect.
- His friend's opinion had an impact on his decision.
- Our choice of concrete will have a tremendous impact on the building's mechanical performance.
- Adjectives often applied to "impact": social, political, physical, positive, negative, good, bad, beneficial, harmful, significant, great, important, strong, big, small, real, huge, likely, actual, potential, devastating, disastrous, true, primary.
- The adposition generally used with "impact" is "on" (such as in last example in section above)
- There are English speakers who are so averse to the verb sense that they have become hypersensitive to the use of the figurative noun sense, with a low threshold for labeling such use as overuse (cliché). In defensive editing, the solution is to replace the figurative noun sense with effect and the verb sense with affect, which nearly always produces an acceptable result. (Rarely, a phrase such as "the impact of late effects" is better stetted to avoid "the effect of [...] effects".)
- The translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Wiktionary:Entry layout#Translations.
- (transitive) To collide or strike, the act of impinging.
- When the hammer impacts the nail, it bends.
- (transitive) To compress; to compact; to press into something or pack together.
- The footprints of birds do not impact the soil in the way those of dinosaurs do.
- (transitive, proscribed) To influence; to affect; to have an impact on.
- I can make the changes, but it will impact the schedule.
- (transitive, rare) To stamp or impress onto something.
- Ideas impacted on the mind.
Some authorities object to the verb sense of impact, meaning "to influence; to affect; to have an impact on". Although most verbification instances in English draw no prescriptive attention, a few do, including this one. To avoid annoying those readers who care, one can replace the verb sense with affect, which nearly always produces an acceptable result. See also the usage note for the noun sense.