supererogatory

from WordNet (r) 3.0 (2006)

supererogatory
    adj 1: more than is needed, desired, or required; "trying to
           lose excess weight"; "found some extra change lying on
           the dresser"; "yet another book on heraldry might be
           thought redundant"; "skills made redundant by
           technological advance"; "sleeping in the spare room";
           "supernumerary ornamentation"; "it was supererogatory of
           her to gloat"; "delete superfluous (or unnecessary)
           words"; "extra ribs as well as other supernumerary
           internal parts"; "surplus cheese distributed to the
           needy" [syn: {excess}, {extra}, {redundant}, {spare},
           {supererogatory}, {superfluous}, {supernumerary},
           {surplus}]

from The Collaborative International Dictionary of English v.0.48

Supererogatory \Su`per*e*rog"a*to*ry\, a.
   Performed to an extent not enjoined, or not required, by duty
   or necessity; as, supererogatory services. --Howell.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

25 Moby Thesaurus words for "supererogatory":
      de trop, dispensable, excess, expendable, expletive, gratuitous,
      in excess, needless, nonessential, pleonastic, prolix, redundant,
      spare, superfluous, supernumerary, tautologic, tautologous,
      to spare, unasked, uncalled-for, unessential, unnecessary,
      unneeded, verbose, wanton