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

sadness \sad"ness\, n.
   1. heaviness; firmness. obs.
      1913 webster

   2. seriousness; gravity; discretion. obs.
      1913 webster

            her sadness and her benignity.        --chaucer.
      1913 webster

   3. quality of being sad, or unhappy; gloominess;
      sorrowfulness; dejection.
      1913 webster

            dim sadness did not spare
            that time celestial visages.          --milton.
      1913 webster

   syn: sorrow; heaviness; dejection. see grief.
        1913 webster
see also:
grief 

[2] : WordNet (r) 2.0

sadness
     n 1: emotions experienced when not in a state of well-being syn:
           unhappiness ant: happiness
     2: the state of being sad; "she tired of his perpetual sadness"
        syn: sorrow, sorrowfulness
see also:
unhappiness happiness sorrow sorrowfulness 

[3] : Moby Thesaurus II by Grady Ward, 1.0

111 moby thesaurus words for "sadness":
   aching heart, agony, agony of mind, anguish, bale, beggarliness,
   bitterness, blackishness, bleakness, bleeding heart, blue devils,
   blues, broken heart, cheapness, cheerlessness, comfortlessness,
   contemptibleness, crumminess, crushing, darkishness, darkness,
   darksomeness, dejectedness, dejection, depression, depth of misery,
   desolation, despair, despicableness, despondency, dinge,
   discomfort, disconsolateness, disconsolation, dismalness,
   dispiritedness, distress, distressfulness, doldrums, dolor,
   downcastness, downheartedness, downs, dreariness, dumps, duskiness,
   duskness, extremity, forlornness, funereality, funk, gaudiness,
   gloom, gloominess, graveness, grief, grievousness, heartache,
   heavy heart, heavyheartedness, hopelessness, infelicity,
   joylessness, lamentability, lamentation, listlessness, meanness,
   megrims, melancholia, melancholy, meretriciousness, meritlessness,
   miserableness, misery, moodiness, mopes, mournfulness, mourning,
   pain, painfulness, paltriness, pathos, pitiability, pitiableness,
   pitifulness, poignancy, poorness, prostration, regrettableness,
   shabbiness, sharpness, shoddiness, soberness, sobriety, somberness,
   sorriness, sorrow, sorrowfulness, suds, suicidal despair, swarth,
   swarthiness, swartness, unhappiness, unworthiness, vileness, woe,
   woebegoneness, woefulness, worthlessness, wretchedness

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