Source : Webster's Revised Unabridged Dictionary (1913)

Corrosion \Cor*ro"sion\ (k?r-r?"zh?n), n. [LL. corrosio: cf. F.
   corrosion. See {Corrode}.]
   The action or effect of corrosive agents, or the process of
   corrosive change; as, the rusting of iron is a variety of
   corrosion.

         Corrosion is a particular species of dissolution of
         bodies, either by an acid or a saline menstruum. --John
                                                  Quincy.

Source : WordNet®

corrosion
     n 1: a state of deterioration in metals caused by oxidation or
          chemical action
     2: erosion by chemical action [syn: {corroding}, {erosion}]