quinine
n//kwɪˈniːn//kinin
(pharmaceutical drug) An alkaloid with the chemical formula C20H24N2O2, originally derived from cinchona bark (from plants of the genus Cinchona), used to treat malaria and as an ingredient of tonic water, which presents as a bitter colourless powder; also, a drug containing quinine or a chemical compound derived from it. [from early 19th c.]