a white, bitter, crystalline alkaloid, C 17 H 19 NO 3 ⋅H 2 O, the most important narcotic and addictive principle of opium, obtained by extraction and crystallization and used chiefly in medicine as a pain reliever and sedative.
1828, from Fr. morphine or Ger. Morphin (1816), name coined in allusion to L. Morpheus, Ovid's name for the god of dreams, from Gk. morphe "form, shape, beauty, outward appearance," perhaps from PIE *merph-, a possible Gk. root meaning "form," of unknown origin. So called because of the drug's sleep-inducing properties.
morphine mor·phine (môr'fēn') n. A bitter crystalline alkaloid extracted from opium, the soluble salts of which are used in medicine as an analgesic, a light anesthetic, or a sedative. Also called morphia.