The Collaborative International Dictionary of English v.0.48:

Curable \Cur"a*ble\ (k?r"?-b'l), a. [Cf. F. curable. See Cure,
   v. t.]
   Capable of being cured; admitting remedy. "Curable diseases."
   --Harvey. -- Cur"a*ble*ness, n. -- Cur`a*bly, adv.
   [1913 Webster] Cura[,c]ao

WordNet (r) 3.0 (2006):

curableness
    n 1: capability of being cured or healed [syn: curability,
         curableness] [ant: incurability, incurableness]