Stimulator

to rouse to action or effort, as by encouragement or pressure; spur on; incite

to stimulate his interest in mathematics.

Physiology, Medicine/Medical . to excite (a nerve, gland, etc.) to its functional activity.

to invigorate (a person) by a food or beverage containing a stimulant, as coffee, tea, or alcoholic liquor.

to act as a stimulus or stimulant.

noun

encouragement , fillip , impetus , impulse , incentive , inducement , motivation , prod , push , spur , stimulant , stimulation