The Collaborative International Dictionary of English v.0.48:

Embellish \Em*bel"lish\, v. t. [imp. & p. p. Embellished; p.
   pr. & vb. n. Embellishing.] [OE. embelisen, embelisshen, F.
   embellir; pref. em- (L. in) + bel, beau, beautiful. See
   Beauty.]
   To make beautiful or elegant by ornaments; to decorate; to
   adorn; as, to embellish a book with pictures, a garden with
   shrubs and flowers, a narrative with striking anecdotes, or
   style with metaphors.

   Syn: To adorn; beautify; deck; bedeck; decorate; garnish;
        enrich; ornament; illustrate. See Adorn.
        [1913 Webster]

WordNet (r) 3.0 (2006):

embellish
    v 1: add details to [syn: embroider, pad, lard,
         embellish, aggrandize, aggrandise, blow up,
         dramatize, dramatise]
    2: be beautiful to look at; "Flowers adorned the tables
       everywhere" [syn: deck, adorn, decorate, grace,
       embellish, beautify]
    3: make more attractive by adding ornament, colour, etc.;
       "Decorate the room for the party"; "beautify yourself for the
       special day" [syn: decorate, adorn, grace, ornament,
       embellish, beautify]
    4: make more beautiful [syn: fancify, beautify, embellish,
       prettify] [ant: uglify]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "embellish":
   adorn, apparel, array, beautify, bedeck, bedizen, belie, blazon,
   camouflage, caparison, color, convolute, cultivate, dandify, deck,
   deck out, decorate, develop, disguise, distort, dizen, doll up,
   dress, dress up, elaborate, emblazon, embroider, enhance, enrich,
   evolve, exaggerate, falsify, festoon, fig out, finish, fix up,
   flourish, fudge, furbish, furbish up, garble, garnish, gild,
   gild the lily, gloss, gloss over, grace, gussy up, improve,
   involve, load with ornament, magnify, mask, mature, miscite,
   miscolor, misquote, misreport, misrepresent, misstate, ornament,
   overcharge, overdo, overdraw, overlay, overload, overpaint,
   overstate, pad, paint, perfect, pervert, polish, prank, prank up,
   preen, prettify, primp, primp up, prink, prink up, redecorate,
   redo, refine, refurbish, ripen, season, set off, set out, slant,
   smarten, smarten up, spruce up, strain, titivate, trick out,
   trick up, trim, twist, understate, varnish, warp, whitewash