The Collaborative International Dictionary of English v.0.48:

Nimiety \Ni*mi"e*ty\, n. [L. nimietas, fr. nimius, a., nimis,
   adv., too much.]
   State of being in excess. [R.]
   [1913 Webster]

         There is a nimiety, a too-muchness, in all Germans.
                                                  --Coleridge.
   [1913 Webster]

WordNet (r) 3.0 (2006):

nimiety
    n 1: a quantity much larger than is needed [syn: excess,
         surplus, surplusage, nimiety]