Definify.com
Webster 1913 Edition
Impetus
Im′pe-tus
(ĭm′pē̍-tŭs)
, Noun.
1.
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.
☞ Momentum is the technical term, impetus its popular equivalent, yet differing from it as applied commonly to bodies moving or moved suddenly or violently, and indicating the origin and intensity of the motion, rather than its quantity or effectiveness.
3.
(Gun.)
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.
Webster 1828 Edition
Impetus
IM'PETUS
,Noun.
1.
The force with which one body in motion strikes another.