The Collaborative International Dictionary of English v.0.48:

Benignity \Be*nig"ni*ty\, n. [OE. benignite, F. b['e]nignit['e],
   OF. b['e]nignet['e], fr. L. benignitas. See Benign.]
   1. The quality of being benign; goodness; kindness;
      graciousness. "Benignity of aspect." --Sir W. Scott.
      [1913 Webster]

   2. Mildness; gentleness.
      [1913 Webster]

            The benignity or inclemency of the season.
                                                  --Spectator.
      [1913 Webster]

   3. Salubrity; wholesome quality. --Wiseman.
      [1913 Webster]

WordNet (r) 3.0 (2006):

benignity
    n 1: the quality of being kind and gentle [syn: benignity,
         benignancy, graciousness] [ant: malignance,
         malignancy, malignity]
    2: a kind act [syn: kindness, benignity]