What does "impulse" mean?

Additional senses

1. 2.(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.
2. 3.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.
3. 4.To impel; to incite. [Obs.] Pope.