c. 1600, "press closely into something," from Latin impactus, past participle of impingere "to push into, drive into, strike against," from assimilated form of in- "into, in, on, upon" (from PIE root *en "in") + pangere "to fix, fasten" (from PIE root *pag- "to fasten"). Original sense is preserved in impacted teeth. Sense of "strike forcefully against something" first recorded 1916. Figurative sense of "have a forceful effect on" is from 1935. Related: Impacting.