1. (a.) Tending to excite; exciting.

2. (n.) An agent or influence which arouses vital activity, or produces increased action, in a living organism or in any of its tissues or parts; a stimulant.

actuation archetypal pattern archetype atomic power automatic writing automatism blind impulse catalyst collective unconscious compulsion compulsiveness conditioning constraint drive echolalia echopraxia electric power electropower excitant exigency forwardness goad haste hastiness horsepower hydraulic power hydroelectric power id impetus impulsion impulsiveness inborn proclivity incentive incitation incitement instinct instinctiveness involuntariness jet power libido lust manpower motivation natural instinct natural tendency nuclear power overhastiness passion pinch piston power precipitation precociousness precocity prematureness prematurity press pressure primitive self propulsion push rash impulse reflex action rocket power rush sheer chemistry solar power spur steam power stimulant stress subconscious urge thermonuclear power thrust unlearned capacity unreasoning impulse untimeliness unwilledness urge urgency vital impulse water power