Source : Webster's Revised Unabridged Dictionary (1913)

Ameliorate \A*mel"io*rate\, v. t. [imp. & p. p. {Ameliorated};
   p. pr. & vb. n. {Ameliorating}.] [L. ad + meliorare to make
   better: cf. F. am['e]liorer. See {Meliorate}.]
   To make better; to improve; to meliorate.

         In every human being there is a wish to ameliorate his
         own condition.                           --Macaulay.

Ameliorate \A*mel"io*rate\, v. i.
   To grow better; to meliorate; as, wine ameliorates by age.

Source : WordNet®

ameliorate
     v 1: to make better; "The editor improved the manuscript with his
          changes" [syn: {better}, {improve}, {amend}, {meliorate}]
          [ant: {worsen}]
     2: get better; "The weather improved toward evening" [syn: {better},
         {improve}, {meliorate}] [ant: {worsen}]