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]