from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An impelling force; an impulse.
- n. The force or energy associated with a moving body.
- n. Something that incites; a stimulus.
- n. Increased activity in response to a stimulus: The approaching deadline gave impetus to the investigation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Something that impels, a stimulating factor.
- n. A force, either internal or external, that impels; an impulse.
- n. The force or energy associated with a moving body; a stimulus.
- n. An activity in response to a stimulus.
from the GNU version of the Collaborative International Dictionary of English
- n. A property possessed by a moving body in virtue of its weight and its motion; the force with which any body is driven or impelled; momentum.
- n. Fig.: Impulse; incentive; stimulus; vigor; force.
- n. The altitude through which a heavy body must fall to acquire a velocity equal to that with which a ball is discharged from a piece.
from The Century Dictionary and Cyclopedia
- n. Energy of motion; the power with which a moving body tends to maintain its velocity and overcome resistance: as, the impetus of a cannon-ball; hence, figuratively, impulse; impulsion; stimulus.
- n. In gunnery, the altitude due to the first force of projection, or the space through which a body must fall to acquire a velocity equal to that with which a ball is discharged from a piece.
- n. The sudden force of passion.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the act of applying force suddenly
- n. a force that moves something along
Middle English impetous, from Latin impetus, from impetere, to attack : in-, against; + petere, to go towards, seek.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin impetus ("a rushing upon, an attack, assault, onset"), from impetere ("to rush upon, attack"), from in ("upon") + petere ("to seek, fall upon"). (Wiktionary)