/ Dictionary / Index I impact wrench: Meaning and Definition of Find definitions for: im'pact wrench" Pronunciation: [key] an electric or pneumatic power wrench with interchangeable toolhead attachments, used for installing and removing nuts, bolts, and screws. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. impact parameter impair Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language