Definition of stimulant

• a. - Serving to stimulate.
• a. - Produced increased vital action in the organism, or in any of its parts.
• n. - That which stimulates, provokes, or excites.
• n. - An agent which produces a temporary increase of vital activity in the organism, or in any of its parts; -- sometimes used without qualification to signify an alcoholic beverage used as a stimulant.