IMPULSION
impulse, impulsion, impetus
(noun) the act of applying force suddenly; “the impulse knocked him over”
drift, impetus, impulsion
(noun) a force that moves something along
Source: WordNet® 3.1
Etymology
Noun
impulsion (countable and uncountable, plural impulsions)
The act of impelling or driving onward, or the state of being impelled; the sudden or momentary agency of a body in motion on another body; also, the impelling force, or impulse.
Influence acting unexpectedly or temporarily on the mind; sudden motive or influence; impulse.
Source: Wiktionary
Im*pul"sion, n. Etym: [L. impulsio: cf. F. impulsion. See Impel.]
1. The act of impelling or driving onward, or the state of being
impelled; the sudden or momentary agency of a body in motion on
another body; also, the impelling force, or impulse. "The impulsion
of the air." Bacon.
2. Influence acting unexpectedly or temporarily on the mind; sudden
motive or influence; impulse. "The impulsion of conscience."
Clarendon. "Divine impulsion prompting." Milton.
Source: Webster’s Unabridged Dictionary 1913 Edition