The Collaborative International Dictionary of English v.0.48:

Meritable \Mer"it*a*ble\, a.
   Deserving of reward. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

meritable
    adj 1: deserving reward or praise; "a lifetime of meritorious
           service"; "meritorious conduct" [syn: meritorious,
           meritable]