The Collaborative International Dictionary of English v.0.48:

Degradation \Deg`ra*da"tion\, n. [LL. degradatio, from
   degradare: cf. F. d['e]gradation. See Degrade.]
   1. The act of reducing in rank, character, or reputation, or
      of abasing; a lowering from one's standing or rank in
      office or society; diminution; as, the degradation of a
      peer, a knight, a general, or a bishop.
      [1913 Webster]

            He saw many removes and degradations in all the
            other offices of which he had been possessed.
                                                  --Clarendon.
      [1913 Webster]

   2. The state of being reduced in rank, character, or
      reputation; baseness; moral, physical, or intellectual
      degeneracy; disgrace; abasement; debasement.
      [1913 Webster]

            The . . . degradation of a needy man of letters.
                                                  --Macaulay.
      [1913 Webster]

            Deplorable is the degradation of our nature.
                                                  --South.
      [1913 Webster]

            Moments there frequently must be, when a sinner is
            sensible of the degradation of his state. --Blair.
      [1913 Webster]

   3. Diminution or reduction of strength, efficacy, or value;
      degeneration; deterioration.
      [1913 Webster]

            The development and degradation of the alphabetic
            forms can be traced.                  --I. Taylor
                                                  (The
                                                  Alphabet).
      [1913 Webster]

   4. (Geol.) A gradual wearing down or wasting, as of rocks and
      banks, by the action of water, frost etc.
      [1913 Webster]

   5. (Biol.) The state or condition of a species or group which
      exhibits degraded forms; degeneration.
      [1913 Webster]

            The degradation of the species man is observed in
            some of its varieties.                --Dana.
      [1913 Webster]

   6. (Physiol.) Arrest of development, or degeneration of any
      organ, or of the body as a whole.
      [1913 Webster]

   Degradation of energy, or Dissipation of energy
      (Physics), the transformation of energy into some form in
      which it is less available for doing work.

   Syn: Abasement; debasement; reduction; decline.
        [1913 Webster]

WordNet (r) 3.0 (2006):

degradation
    n 1: changing to a lower state (a less respected state) [syn:
         degradation, debasement]
    2: a low or downcast state; "each confession brought her into an
       attitude of abasement"- H.L.Menchken [syn: abasement,
       degradation, abjection]

Moby Thesaurus II by Grady Ward, 1.0:

198 Moby Thesaurus words for "degradation":
   abandon, abandonment, abasement, abjection, abjectness, ablation,
   abominableness, atomization, atrociousness, banishment, baseness,
   beggarliness, biodegradability, biodegradation, blackballing,
   breakup, bump, bust, casting down, chicanery, comedown, concavity,
   contemptibility, contemptibleness, corrosion, corruptedness,
   corruption, corruptness, crumbling, crumminess, de-escalation,
   debasement, decadence, decadency, decay, declension, declination,
   decline, decomposition, deformation, defrocking, degeneracy,
   degenerateness, degeneration, degradability, degrading,
   demoralization, demotion, depluming, deportation, depravation,
   depravedness, depravity, depreciation, depression, deprivation,
   derogation, descent, despicableness, deterioration, detrusion,
   devolution, dilapidation, diminution, disbarment, discredit,
   disfellowship, disgrace, disgrading, dishonor, disintegration,
   disjunction, disorganization, displuming, disrepute, dissoluteness,
   dissolution, downgrading, downtrend, downturn, downward mobility,
   downward trend, drop, ducking, dying, ebb, effeteness, enormity,
   erosion, exclusion, excommunication, execrableness, exile,
   expatriation, extradition, fading, failing, failure,
   failure of nerve, fall, falling-off, foulness, fugitation,
   fulsomeness, grossness, hauling down, heinousness, hollowness,
   humbling, humiliation, ignobility, ignominiousness, ignominy,
   incoherence, infamousness, infamy, ingloriousness, involution,
   knavery, knavishness, lapse, littleness, loss of honor,
   loss of tone, lowering, lowness, meanness, mildew, miserableness,
   mold, monstrousness, moral pollution, moral turpitude,
   nefariousness, obloquy, obnoxiousness, odiousness, odium,
   opprobrium, ostracism, ostracization, outlawing, outlawry,
   oxidation, oxidization, paltriness, pettiness, pokiness, poorness,
   profligacy, rankness, rascality, rascalry, ravages of time,
   reduction, regression, relegation, reprobacy, resolution,
   retrocession, retrogradation, retrogression, roguery, roguishness,
   rottenness, rust, rustication, scabbiness, scampishness,
   scoundrelism, scrubbiness, scruffiness, scumminess, scurviness,
   shabbiness, shame, shoddiness, sinking, slippage, slump, smallness,
   spoilage, squalor, stripping, stripping of rank, submergence,
   thrusting under, transportation, turpitude, unfrocking, vileness,
   villainousness, villainy, vitiation, wane, wear, wear and tear,
   wretchedness



Bouvier's Law Dictionary, Revised 6th Ed (1856):

DEGRADATION, punishment, ecclesiastical law. A censure by which a clergy man
is deprived of his holy orders, which he had as a priest or deacon.



The Devil's Dictionary (1881-1906):

DEGRADATION, n.  One of the stages of moral and social progress from
private station to political preferment.