1. A physical force of one thing hitting another: The driver of the car probably died on impact when the terrible accident occurred.
2. An influence or a significant effect: The continuous snowfall and ice storms that have been going on in many parts of the U.S. have had a big impact on driving conditions.

1. To force, to wedge, or to squeeze together with a forcible action with another object: The large boulder rolling down the hill impacted with three houses before it stopped moving.
2. To cause something to change or to have a strong influence on: High interest rates are impacting the housing market in a negative way.