Source : Webster's Revised Unabridged Dictionary (1913)

Revocation \Rev`o*ca"tion\, n. [L. revocatio: cf. F.
   r['e]vocation.]
   1. The act of calling back, or the state of being recalled;
      recall.

            One that saw the people bent for the revocation of
            Calvin, gave him notice of their affection.
                                                  --Hooker.

   2. The act by which one, having the right, annuls an act
      done, a power or authority given, or a license, gift, or
      benefit conferred; repeal; reversal; as, the revocation of
      an edict, a power, a will, or a license.

Source : WordNet®

revocation
     n 1: the state of being cancelled or annulled [syn: {annulment}]
     2: the act (by someone having the authority) of annulling
        something previously done; "the revocation of a law"