[1] : The Collaborative International Dictionary of English v.0.48

sullen \sul"len\, a. oe. solein, solain, lonely, sullen;
   through old french fr. assumed ll. solanus solitary, fr. l.
   solus alone. see sole, a.
   1. lonely; solitary; desolate. obs. --wyclif job iii. 14.
      1913 webster

   2. gloomy; dismal; foreboding. --milton.
      1913 webster

            solemn hymns so sullen dirges change. --shak.
      1913 webster

   3. mischievous; malignant; unpropitious.
      1913 webster

            such sullen planets at my birth did shine. --dryden.
      1913 webster

   4. gloomily angry and silent; cross; sour; affected with ill
      humor; morose.
      1913 webster

            and sullen i forsook the imperfect feast. --prior.
      1913 webster

   5. obstinate; intractable.
      1913 webster

            things are as sullen as we are.       --tillotson.
      1913 webster

   6. heavy; dull; sluggish. "the larger stream was placid, and
      even sullen, in its course." --sir w. scott.
      1913 webster

   syn: sulky; sour; cross; ill-natured; morose; peevish;
        fretful; ill-humored; petulant; gloomy; malign;
        intractable.

   usage: sullen, sulky. both sullen and sulky show
          themselves in the demeanor. sullenness seems to be an
          habitual sulkiness, and sulkiness a temporary
          sullenness. the former may be an innate disposition;
          the latter, a disposition occasioned by recent injury.
          thus we are in a sullen mood, and in a sulky fit.
          1913 webster

                no cheerful breeze this sullen region knows;
                the dreaded east is all the wind that blows.
                                                  --pope.
          1913 webster -- sul"lenly, adv. --
          sul"lenness, n.
          1913 webster
see also:
sole sullen sulky sul"lenly sul"lenness 

[2] : WordNet (r) 2.0

sullenness
     n 1: a gloomy ill-tempered feeling syn: moroseness, glumness
     2: a sullen moody resentful disposition syn: sulkiness, moroseness,
         sourness
see also:
moroseness glumness sulkiness sourness 

Sullenness >> S Words
Sullenness, definition of term: Sullenness
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