The Collaborative International Dictionary of English v.0.48:

Putrefaction \Pu`tre*fac"tion\, n. [L. putrefactio: cf. F.
   putr['e]faction. See Putrefy.]
   1. The act or the process of putrefying; the offensive decay
      of albuminous or other matter.
      [1913 Webster]

   Note: Putrefaction is a complex phenomenon involving a
         multiplicity of chemical reactions, always accompanied
         by, and without doubt caused by, bacteria and
         vibriones; hence, putrefaction is a form of
         fermentation, and is sometimes called putrefaction
         fermentative. Putrefaction is not possible under
         conditions that preclude the development of living
         organisms. Many of the products of putrefaction are
         powerful poisons, and are called cadaveric poisons, or
         ptoma["i]nes.
         [1913 Webster]

   2. The condition of being putrefied; also, that which
      putrefied. "Putrefaction's breath." --Shelley.
      [1913 Webster]

WordNet (r) 3.0 (2006):

putrefaction
    n 1: a state of decay usually accompanied by an offensive odor
         [syn: putrefaction, rot]
    2: (biology) the process of decay caused by bacterial or fungal
       action [syn: decomposition, rot, rotting,
       putrefaction]
    3: 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]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "putrefaction":
   caries, carrion, decay, decomposition, dry rot, foulness, gangrene,
   mortification, necrosis, putrescence, putridity, putridness,
   rancidity, rancidness, rankness, rot, rottenness, slough,
   sphacelation, sphacelus, spoilage, tooth decay