The Collaborative International Dictionary of English v.0.48:

forgivingness \forgivingness\ n.
   a tendency to be kind and forgiving.

   Syn: kindness.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Forgiving \For*giv"ing\, a.
   Disposed to forgive; inclined to overlook offenses; mild;
   merciful; compassionate; placable; as, a forgiving temper. --
   For*giv"ing*ly, adv. -- For*giv"ing*ness, n. --J. C.
   Shairp.
   [1913 Webster]

WordNet (r) 3.0 (2006):

forgivingness
    n 1: tendency to be kind and forgiving [syn: forgivingness,
         kindness]