■ noun
1》 a sudden strong and unreflective urge to act.
2》 an impetus.
3》 a pulse of electrical energy; a brief current.
4》 Physics a force acting briefly on a body and producing a change of momentum.
Origin
C17 (earlier (ME) as impulsion ), as a verb in the sense 'give an ~ to', from L. impuls- , impellere (see impel ).