noun im·pe·tus \ˈim-pə-təs\

Definition of impetus

  1. 1a (1) :  a driving force :  impulse (2) :  incentive, stimulusb :  stimulation or encouragement resulting in increased activity

  2. 2 :  the property possessed by a moving body in virtue of its mass and its motion —used of bodies moving suddenly or violently to indicate the origin and intensity of the motion

impetus was our Word of the Day on 08/07/2013. Hear the podcast!

Examples of impetus in a sentence

  1. In a revealing comment, Mr. Updike says an impetus for Rabbit, Run was the “threatening” success of Jack Kerouac's On the Road, the signature book of the 1950s Beat Generation, and its frenetic search for sensation. —Dennis Farney, Wall Street Journal, 16 Sept. 1992

  2. But 1939 gave new impetus to the Western with the Cecil B. de Mille railway epic Union Pacific, John Ford's skillful and dramatic Stagecoach,  … and George Marshall's classic comic Western, Destry Rides Again. —Ira Konigsberg, The Complete Film Dictionary, 1987

  3. … new techniques of navigation and shipbuilding enlarged trade and the geographical horizon; newly centralized power absorbed from the declining medieval communes was at the disposal of the monarchies and the growing nationalism of the past century gave it impetus … —Barbara W. Tuchman, The March of Folly, 1984

  4. His discoveries have given impetus to further research.

  5. the reward money should be sufficient impetus for someone to come forward with information about the robbery

Did You Know?

You already have plenty of incentive to learn the origin of "impetus," so we won't force the point. "Impetus" comes from Latin, where it means "attack or assault"; the verb "impetere" was formed by combining the prefix in- with petere, meaning "to go to or seek." "Petere" also gives us other words suggesting a forceful urging or momentum, such as "appetite," "perpetual," and "centripetal." "Impetus" describes the kind of force that encourages an action ("the impetus behind the project") or the momentum of an action already begun ("the meetings only gave impetus to the rumors of a merger").

Origin and Etymology of impetus

Latin, assault, impetus, from impetere to attack, from in- + petere to go to, seek — more at feather

First Known Use: 1641

IMPETUS Defined for English Language Learners


noun im·pe·tus \ˈim-pə-təs\

Definition of impetus for English Language Learners

  • : a force that causes something (such as a process or activity) to be done or to become more active

  • : a force that causes an object to begin moving or to continue to move

Seen and Heard

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to cast off or become cast off

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