/ Dictionary / Index S sullen: Meaning and Definition of Find definitions for: sul•len Pronunciation: (sul'un), [key] — adj. showing irritation or ill humor by a gloomy silence or reserve. persistently and silently ill-humored; morose. indicative of gloomy ill humor. gloomy or dismal, as weather or a sound. sluggish, as a stream. malignant, as planets or influences. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sullen (Thesaurus) sullage Sullivan Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language