NOUN (2)

1. the act of cancelling; calling off some arrangement;

2. the speech act of revoking or annulling or making void;

The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. (Math.) The operation of striking out common factors, in
      both the dividend and divisor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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