WordNet (r) 3.0 (2006):

spoilage
    n 1: the amount that has spoiled
    2: the process of becoming spoiled [syn: spoilage, spoiling]
    3: the act of spoiling something by causing damage to it; "her
       spoiling my dress was deliberate" [syn: spoil, spoiling,
       spoilage]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "spoilage":
   biodegradability, biodegradation, breakup, caries, carrion,
   corrosion, corruption, decay, decomposition, degradability,
   degradation, dilapidation, disintegration, disorganization,
   dissolution, dry rot, foulness, gangrene, mildew, mold,
   mortification, necrosis, oxidation, oxidization, putrefaction,
   putrescence, putridity, putridness, rancidity, rancidness,
   rankness, resolution, rot, rottenness, rust, slough, sphacelation,
   sphacelus, tooth decay