Definition of "impact" in English

noun

1. The striking of one body against another; collision.

2. The force or energy of a collision of two objects.

   • The hatchet cut the wood on impact.

3. (chiefly medicine) A forced impinging.

   • His spine had an impingement; L4 and L5 made impact, which caused numbness in his leg.

4. (figurative, proscribed) A significant or strong influence or 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.
   • December 7, 1941, November 22, 1963, and September 11, 2001 had an impact on many throughout the world.
   • The French revolution, the Russian revolution, and the Iranian revolution had an impact on many throughout the world.

verb

1. (transitive) To collide or strike, the act of impinging.

   • When the hammer impacts the nail, it bends.

2. (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.

3. (transitive, figurative, proscribed) To significantly or strongly influence or affect; to have an impact on.

   • I can make the changes, but it will impact the schedule.

4. (transitive, rare) To stamp or impress onto something.

   • Ideas impacted on the mind.