Pronunciation: (kwī'nīn, kwin'īn or, esp. Brit., kwi-nēn'), [key]
—n. Chem., Pharm.
1. a white, bitter, slightly water-soluble alkaloid, C20H24N2O2, having needlelike crystals, obtained from cinchona bark: used in medicine chiefly in the treatment of resistant forms of malaria.
2. a salt of this alkaloid, esp. the sulfate.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.