The Collaborative International Dictionary of English v.0.48:

Consumption \Con*sump"tion\ (?; 215), n. [L. consumptio: cf. F.
   consomption.]
   1. The act or process of consuming by use, waste, etc.;
      decay; destruction.
      [1913 Webster]

            Every new advance of the price to the consumer is a
            new incentive to him to retrench the quality of his
            consumption.                          --Burke.
      [1913 Webster]

   2. The state or process of being consumed, wasted, or
      diminished; waste; diminution; loss; decay.
      [1913 Webster]

   3. (Med.) A progressive wasting away of the body; esp., that
      form of wasting, attendant upon pulmonary phthisis and
      associated with cough, spitting of blood, hectic fever,
      etc.; pulmonary phthisis; -- called also pulmonary
      consumption.
      [1913 Webster]

   Consumption of the bowels (Med.), inflammation and
      ulceration of the intestines from tubercular disease.

   Syn: Decline; waste; decay. See Decline.
        [1913 Webster]

WordNet (r) 3.0 (2006):

consumption
    n 1: the process of taking food into the body through the mouth
         (as by eating) [syn: consumption, ingestion, intake,
         uptake]
    2: involving the lungs with progressive wasting of the body
       [syn: pulmonary tuberculosis, consumption, phthisis,
       wasting disease, white plague]
    3: (economics) the utilization of economic goods to satisfy
       needs or in manufacturing; "the consumption of energy has
       increased steadily" [syn: consumption, economic
       consumption, usance, use, use of goods and services]
    4: the act of consuming something [syn: consumption, using
       up, expenditure]

Moby Thesaurus II by Grady Ward, 1.0:

149 Moby Thesaurus words for "consumption":
   Sanforizing, TB, ablation, active use, aerogenic tuberculosis,
   appetite, appliance, application, atrophy, attenuation, attrition,
   bloodbath, blue ruin, breakup, cannibalism, carnage, carnivorism,
   carnivority, carnivorousness, cerebral tuberculosis, chewing,
   colliquation, corrosion, cropping, damnation, decimation, decrease,
   decrement, deglutition, deliquescence, depletion, depreciation,
   depredation, desolation, despoilment, despoliation, destruction,
   devastation, devouring, devourment, dieting, dining,
   disintegration, disorganization, disruption,
   disseminated tuberculosis, dissipation, dissolution, drain, drying,
   drying up, eating, emaceration, emaciation, employ, employment,
   epulation, erosion, evaporation, exercise, exertion, exhaustion,
   expenditure, feasting, feeding, gluttony, gobbling, good use,
   grazing, hard usage, hard use, havoc, hecatomb, herbivorism,
   herbivority, herbivorousness, holocaust, hunger, ill use,
   impoverishment, ingestion, leakage, licking, loss, lupus vulgaris,
   manducation, marcescence, mastication, messing, misuse, munching,
   nibbling, nutrition, omnivorism, omnivorousness, omophagy,
   pantophagy, parching, pasture, pasturing, pecking, perdition,
   phthisis, preshrinkage, pulmonary tuberculosis, ravage, regalement,
   relishing, rough usage, ruin, ruination, rumination, savoring,
   scrofula, scrofuloderma, searing, shambles, shrinkage, shrinking,
   shriveling, slaughter, spoliation, tasting, thinning, tuberculosis,
   tuberculosis cutis, tuberculosis luposa, tuberculous meningitis,
   undoing, usage, use, using, using up, vandalism, vegetarianism,
   wastage, waste, wasting, wear and tear, wearing, wearing away,
   white plague, wilting, withering, wolfing, wrack, wrack and ruin,
   wreck, wrong use