/ Dictionary / Index S soporiferous: Meaning and Definition of Find definitions for: sop•o•rif•er•ous Pronunciation: (sop"u-rif'ur-us, sō"pu-), [key] — adj. bringing sleep; soporific. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: soporiferous (Thesaurus) sopor soporific Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language