stimulant

noun

1. A substance that acts to increase physiological or nervous activity in the body.

   “Milk of chameleon was recommended as an erotic stimulant by Avicenna.”

2. Something that promotes activity, interest, or enthusiasm.

   “[T]ouching the much vexed question of stimulants he relished a glass of choice old wine in season as both nourishing and bloodmaking and possessing aperient virtues (notably a good burgundy which he was a staunch believer in) […]”

   “I was never to feel anything comparable under the influence of orthodox religious stimulants.”

adj

1. (not-comparable)Acting as a stimulant.