/ Dictionary / Index S somnifacient: Meaning and Definition of Find definitions for: som•ni•fa•cient Pronunciation: (som"nu-fā'shunt), [key] — adj. causing or inducing sleep. —n. a drug or other agent that induces or tends to induce sleep. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. somnambulism somniferous Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language