The Collaborative International Dictionary of English v.0.48:

Edulcorate \E*dul"co*rate\, v. t. [imp. & p. p. Edulcorated;
   p. pr. & vb. n. Edulcorating.] [L. e out + dulcoratus, p.
   p. of dulcorare to sweeten, fr. dulcor sweetness, fr. dulcis
   sweet: cf. F. ['e]dulcorer.]
   1. To render sweet; to sweeten; to free from acidity.
      [1913 Webster]

            Succory . . . edulcorated with sugar and vinegar.
                                                  --Evelyn.
      [1913 Webster]

   2. (Chem.) To free from acids, salts, or other soluble
      substances, by washing; to purify. [R.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

edulcorate
    v 1: make sweeter in taste [syn: sweeten, dulcify,
         edulcorate, dulcorate] [ant: acetify, acidify,
         acidulate, sour]

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "edulcorate":
   bolt, candy, clarify, clear, decrassify, depurate, distill,
   dulcify, elute, essentialize, extract, filter, filtrate, glaze,
   honey, leach, lixiviate, mull, percolate, purify, rectify, refine,
   saccharify, screen, separate, sieve, sift, spiritualize, strain,
   sublimate, sublime, sugar, sugar off, sugarcoat, sweeten, try,
   winnow