Etymology: Middle English solein solitary, from Anglo-French sulein, solain, perhaps from sol, soul single, sole + -ain after Old French soltain solitary, private, from Late Latin solitaneus, ultimately from Latin solus alone
Date: 14th century
a. gloomily or resentfully silent or repressed <a sullen crowd> b. suggesting a sullen state ; lowering <a sullen countenance> 2. dull or somber in sound or color 3. dismal, gloomy <a sullen morning> 4. moving sluggishly <a sullen river> • sullenly adverb • sullenness noun Synonyms: sullen, glum, morose, surly, sulky, crabbed, saturnine, gloomy mean showing a forbidding or disagreeable mood. sullen implies a silent ill humor and a refusal to be sociable <remained sullen amid the festivities>. glum suggests a silent dispiritedness <a glum candidate left to ponder a stunning defeat>. morose adds to glum an element of bitterness or misanthropy <morose job seekers who are inured to rejection>. surly implies gruffness and sullenness of speech or manner <a typical surly teenager>. sulky suggests childish resentment expressed in peevish sullenness <grew sulky after every spat>. crabbed applies to a forbidding morose harshness of manner <the school's notoriously crabbed headmaster>. saturnine describes a heavy forbidding aspect or suggests a bitter disposition <a saturnine cynic always finding fault>. gloomy implies a depression in mood making for seeming sullenness or glumness <a gloomy mood ushered in by bad news>.
New Collegiate Dictionary. 2001.