Stĭm'ū-lŭs, n.

n.; pl. STĬM'Ū-LĪ. [Lat., for stimulus, allied to Lat. instigare, to stimulate, Gr. στίζειν, to prick, root στιγ.]

1. A goad; hence, something that rouses the mind or spirits; as, the hope of gain is a powerful stimulus to labor and action.
2. (Med.) That which produces an increase of vital action.