rush /rush/ , 1. (Slang) a pleasurable feeling experienced by users of recreational drugs following an injection of amphetamine or heroin. An amphetamine rush is described as an abrupt awakening, as distinguished from the drowsy drifting rush of heroin use. Also called high. See also flash. 2. (in physiology) a strong wave of contractile activity that travels along the small intestine, usually as a result of irritation or distension.
