Source : Webster's Revised Unabridged Dictionary (1913)

Amelioration \A*mel`io*ra"tion\, n. [Cf. F. am['e]lioration.]
   The act of ameliorating, or the state of being ameliorated;
   making or becoming better; improvement; melioration.
   ``Amelioration of human affairs.'' --J. S. Mill.

Source : WordNet®

amelioration
     n : the act of relieving ills and changing for the better [syn:
         {melioration}, {betterment}]