The Collaborative International Dictionary of English v.0.48:

Depravation \Dep`ra*va"tion\ (d[e^]p`r[.a]*v[=a]"sh[u^]n), n.
   [L. depravitio, from depravare: cf. F. d['e]pravation. See
   Deprave.]
   1. Detraction; depreciation. [Obs.]
      [1913 Webster]

            To stubborn critics, apt, without a theme,
            For depravation.                      --Shak.
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   2. The act of depraving, or making anything bad; the act of
      corrupting.
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   3. The state of being depraved or degenerated; degeneracy;
      depravity.
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            The depravation of his moral character destroyed his
            judgment.                             --Sir G. C.
                                                  Lewis.
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   4. (Med.) Change for the worse; deterioration; morbid
      perversion.

   Syn: Depravity; corruption. See Depravity.
        [1913 Webster]

WordNet (r) 3.0 (2006):

depravation
    n 1: moral perversion; impairment of virtue and moral
         principles; "the luxury and corruption among the upper
         classes"; "moral degeneracy followed intellectual
         degeneration"; "its brothels, its opium parlors, its
         depravity"; "Rome had fallen into moral putrefaction" [syn:
         corruption, degeneracy, depravation, depravity,
         putrefaction]