transitive verb

1. to force tightly together; pack; wedge
2. to affect: a usage objected to by some

Etymology: < L impactus, pp. of impingere, to press firmly together: see impinge

intransitive verb

1. to hit with force
2. to have an effect: usually with on: a usage objected to by some

noun

1. a striking together; violent contact; collision
2. the force of a collision; shock
3. the power of an event, idea, etc. to produce changes, move the feelings, etc.