The Collaborative International Dictionary of English v.0.48:

Laudability \Laud`a*bil"i*ty\, n. [L. laudabilitas.]
   Laudableness; praiseworthiness.
   [1913 Webster]

WordNet (r) 3.0 (2006):

laudability
    n 1: the quality of being worthy of praise [syn:
         praiseworthiness, laudability, laudableness]