impetus

n. urge, drive, something which stimulates or impels; momentum, force through which a body moves

Impetus is a stimulus or impulse, a moving force that sparks momentum.Impetus may also refer to:Theory of impetus, an obsolete scientific theory on projectile motion, superseded by the modern theory of inertia"Impetus", the double dotting of a dotted note in music theoryImpetus (dance move), in danceImpetus (album), an album by rock band Clutch"Impetus", Men's and Women's underwear brand made and designed in Portugal
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Noun
1. a force that moves something along
(synonym) drift, impulsion
(hypernym) force
2. the act of applying force suddenly; "the impulse knocked him over"
(synonym) impulse, impulsion
(hypernym) drive, thrust, driving force

n. onrush; momentum, impetus

(n.)
The aititude through which a heavy body must fall to acquire a velocity equal to that with which a ball is discharged from a piece.
  

(n.)
Fig.: Impulse; incentive; vigor; force.
  

(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.