The Collaborative International Dictionary of English v.0.48:

Open-handed \O"pen-hand`ed\, a.
   Generous; liberal; munificent. -- O"pen-hand`ed*ness, n.
   --J. S. Mill.
   [1913 Webster]

WordNet (r) 3.0 (2006):

openhandedness
    n 1: liberality in bestowing gifts; extremely liberal and
         generous of spirit [syn: munificence, largess,
         largesse, magnanimity, openhandedness]