/ Dictionary / Index I impetus: Meaning and Definition of Find definitions for: im•pe•tus Pronunciation: (im'pi-tus), [key] — pl. -tus•es. a moving force; impulse; stimulus: The grant for building the opera house gave impetus to the city's cultural life. (broadly) the momentum of a moving body, esp. with reference to the cause of motion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: impetus (Thesaurus) impetuous impf. Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language