The Collaborative International Dictionary of English v.0.48:

Dejection \De*jec"tion\, n. [L. dejectio a casting down: cf. F.
   d['e]jection.]
   1. A casting down; depression. [Obs. or Archaic] --Hallywell.
      [1913 Webster]

   2. The act of humbling or abasing one's self.
      [1913 Webster]

            Adoration implies submission and dejection. --Bp.
                                                  Pearson.
      [1913 Webster]

   3. Lowness of spirits occasioned by grief or misfortune;
      mental depression; melancholy.
      [1913 Webster]

            What besides,
            Of sorrow, and dejection, and despair,
            Our frailty can sustain, thy tidings bring.
                                                  --Milton.
      [1913 Webster]

   4. A low condition; weakness; inability. [R.]
      [1913 Webster]

            A dejection of appetite.              --Arbuthnot.
      [1913 Webster]

   5. (Physiol.)
      (a) The discharge of excrement.
      (b) F[ae]ces; excrement. --Ray.
          [1913 Webster]

WordNet (r) 3.0 (2006):

dejection
    n 1: a state of melancholy depression
    2: solid excretory product evacuated from the bowels [syn:
       fecal matter, faecal matter, feces, faeces, BM,
       stool, ordure, dejection]

Moby Thesaurus II by Grady Ward, 1.0:

120 Moby Thesaurus words for "dejection":
   BM, Schmerz, Slough of Despond, abstraction, abulia, alienation,
   anxiety, anxiety equivalent, anxiety state, apathy,
   blank despondency, bloody flux, blues, bouderie, bowel movement,
   catatonic stupor, catharsis, compulsion, crap, death wish,
   defecation, dejecta, dejectedness, dejecture, depression, despair,
   desperation, despondency, despondentness, detachment, diarrhea,
   discharge, discouragement, disheartenment, dispiritedness,
   down trip, downcastness, downer, downheartedness, drooping spirits,
   dumpishness, dysentery, effluent, egesta, ejecta, ejectamenta,
   ejection, elation, emotionalism, euphoria, evacuation, excrement,
   excreta, excretes, extravasate, extravasation, exudate, exudation,
   flux, folie du doute, glumness, grimness, grumness, heartlessness,
   hopelessness, hypochondria, hysteria, hysterics, indifference,
   insensibility, lethargy, lientery, loose bowels, low spirits,
   lowness, lowness of spirit, malaise, mania, melancholia,
   melancholy, mental distress, moodiness, moodishness, mopishness,
   moroseness, movement, obsession, oppression,
   pathological indecisiveness, pessimism, preoccupation, psychalgia,
   psychomotor disturbance, purgation, purge, runs,
   self-destructive urge, shit, shits, sinking heart, spiritlessness,
   stool, stupor, suicidal despair, sulkiness, sullenness, surliness,
   taedium vitae, tic, transudate, transudation, trots, turistas,
   twitching, unresponsiveness, voidance, waste, waste matter,
   weariness of life, withdrawal