impact

noun

1. (countable, uncountable)The striking of one body against another; collision.
2. (countable, uncountable)The force or energy of a collision of two objects.

   “The hatchet cut the wood on impact.”

3. (countable, uncountable)A forced impinging.

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

4. (countable, figuratively, proscribed, uncountable)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.”

   “One way to reduce the environmental impact of meat eating is to make livestock more productive.”

verb

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

   “When the hammer impacts the nail, it bends.”

   “As a microbullet impacts the graphene, the diameter of the cone it creates – determined by later examination of the petals – provides a way to measure how much energy the graphene absorbs before breaking.”

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

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

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

   “Ideas impacted on the mind.”