The Collaborative International Dictionary of English v.0.48:

Redundance \Re*dun"dance\ (r?*d?n"dans), Redundancy
\Re*dun"dan*cy\ (-dan*s?), n. [L. redundantia: cf. F.
   redondance.]
   [1913 Webster]
   1. The quality or state of being redundant; superfluity;
      superabundance; excess.
      [1913 Webster]

   2. That which is redundant or in excess; anything superfluous
      or superabundant.
      [1913 Webster]

            Labor . . . throws off redundacies.   --Addison.
      [1913 Webster]

   3. (Law) Surplusage inserted in a pleading which may be
      rejected by the court without impairing the validity of
      what remains.
      [1913 Webster]

WordNet (r) 3.0 (2006):

redundance
    n 1: the attribute of being superfluous and unneeded; "the use
         of industrial robots created redundancy among workers"
         [syn: redundancy, redundance]