/ Dictionary / Index M morphine: Meaning and Definition of Find definitions for: mor•phine Pronunciation: (môr'fēn), [key] — n. Pharm. a white, bitter, crystalline alkaloid, CHNO&multiplydot;HO, 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. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: morphine (Thesaurus) -morphic morphing Related Content Daily Word Quiz: vernacular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language