Im"pulse (?), n. [L. impulsus, fr. impellere. See Impel.]

1. The act of impelling, or driving onward with sudden force; impulsion; especially, force so communicated as to produced motion suddenly, or immediately.

All spontaneous animal motion is performed by mechanical impulse.
S. Clarke.

2. The effect of an impelling force; motion produced by a sudden or momentary force.

3. (Mech.) The action of a force during a very small interval of time; the effect of such action; as, the impulse of a sudden blow upon a hard elastic body.

4. A mental force which simply and directly urges to action; hasty inclination; sudden motive; momentary or transient influence of appetite or passion; propension; incitement; as, a man of good impulses; passion often gives a violent impulse to the will.

These were my natural impulses for the undertaking.

Syn. -- Force; incentive; influence; motive; feeling; incitement; instigation.

Im*pulse" (?), v. t. [See Impel.] To impel; to incite. [Obs.] Pope.