The Collaborative International Dictionary of English v.0.48:

Lenity \Len"i*ty\ (-t[y^]), n. [L. lenitas, fr. lenis soft,
   mild: cf. OF. lenit['e]. See Lenient.]
   The state or quality of being lenient; mildness of temper or
   disposition; gentleness of treatment; softness; tenderness;
   clemency; -- opposed to severity and rigor.
   [1913 Webster]

         His exceeding lenity disposes us to be somewhat too
         severe.                                  --Macaulay.

   Syn: Gentleness; kindness; tenderness; softness; humanity;
        clemency; mercy.
        [1913 Webster]

WordNet (r) 3.0 (2006):

lenity
    n 1: mercifulness as a consequence of being lenient or tolerant
         [syn: lenience, leniency, mildness, lenity]