咖啡因,茶精(興奮劑)
Caffeine \Caf*fe"ine\, n. [Cf. F. caf['e]ine. See {Coffee}.] (Chem.) A white, bitter, crystallizable substance, obtained from coffee. It is identical with the alkaloid {theine} from tea leaves, and with {guaranine} from guarana.
caffeine n : a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects [syn: {caffein}]