Source : Webster's Revised Unabridged Dictionary (1913)

Cancellation \Can`cel*la"tion\, n. [L. cancellatio: cf. F.
   cancellation.]
   1. The act, process, or result of canceling; as, the
      cansellation of certain words in a contract, or of the
      contract itself.

   2. (Math.) The operation of striking out common factors, in
      both the dividend and divisor.

Source : WordNet®

cancellation
     n 1: the act of cancelling; calling off some arrangement
     2: the speech act of revoking or annulling or making void