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)
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. (Dryden)
Origin: L. Impulsus, fr. Impellere. See Impel.