Pronunciation: ( —n.im'pakt; —v.im-pakt'),[key] —n. 1. the striking of one thing against another; forceful contact; collision: The impact of the colliding cars broke the windshield. 2. an impinging: the impact of light on the eye. 3. influence; effect: the impact of Einstein on modern physics. 4. an impacting; forcible impinging: the tremendous impact of the shot. 5. the force exerted by a new idea, concept, technology, or ideology: the impact of the industrial revolution.
—v.t. 1. to drive or press closely or firmly into something; pack in.
2. to fill up; congest; throng: A vast crowd impacted St. Peter's Square. 3. to collide with; strike forcefully: a rocket designed to impact the planet Mars. 4. to have an impact or effect on; influence; alter: The decision may impact your whole career. The auto industry will be impacted by the new labor agreements.
—v.i. 1. to have impact or make contact forcefully: The ball impacted against the bat with a loud noise. 2. to have an impact or effect: Increased demand will impact on sales.