The Collaborative International Dictionary of English v.0.48:

ornament \or"na*ment\, n. [OE. ornement, F. ornement, fr. L.
   ornamentum, fr. ornare to adorn.]
   That which embellishes or adorns; that which adds grace or
   beauty; embellishment; decoration; adornment.
   [1913 Webster]

         The ornament of a meek and quiet spirit. --1 Pet. iii.
                                                  4.
   [1913 Webster]

         Like that long-buried body of the king
         Found lying with his urns and ornaments. --Tennyson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

ornament \or"na*ment\, v. t. [imp. & p. p. Ornamented; p. pr.
   & vb. n. Ornamenting.]
   To adorn; to deck; to embellish; to beautify; as, to ornament
   a room, or a city.
   [1913 Webster]

   Syn: See Adorn.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ornament
    n 1: something used to beautify [syn: decoration, ornament,
         ornamentation]
    v 1: 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]
    2: be an ornament to; "stars ornamented the Christmas tree"

Moby Thesaurus II by Grady Ward, 1.0:

222 Moby Thesaurus words for "ornament":
   acciaccatura, add, adjoin, adjunct, adorn, adornment, affix,
   agglutinate, anacrusis, annex, append, appoggiatura, arabesque,
   arrangement, array, asiaticism, attach, bass passage, beauties,
   beautify, bedeck, bedizen, blazon, blue ribbon, bonus, bourdon,
   bridge, burden, cadence, cadenza, chorus, coda, color,
   color patterns, coloratura, colors, colors of rhetoric, complicate,
   conjoin, convolute, cordon, cordon bleu, credit, dandify, deck,
   deck out, decor, decorate, decoration, decoration of honor,
   development, device, distinction, division, dizen, doll up, dress,
   dress up, elaborate, elaboration, elegant variation, embellish,
   embellishment, emblazon, emblazonment, emblazonry, embroider,
   embroidery, encumber, enrich, euphuism, exposition, extra,
   extra added attraction, extra dash, festoon, fig out,
   figurative language, figurativeness, figure, figure of speech,
   filigree, filling, fillip, fine writing, fioritura, fix up, flight,
   floridity, floridness, flourish, flower, flower arrangement,
   floweriness, flowers of speech, flowery style, folderol, frill,
   furbish, furniture arrangement, garnish, garnishment, garniture,
   garter, gild, glory, glue on, gold star, grace, grace note,
   grand cordon, great honor, gussy up, harmonic close, hitch on,
   honor, illumination, image, imagery, incidental, incidental note,
   infix, interlude, intermezzo, introductory phrase, involve,
   join with, lagniappe, load with ornament, long mordent, lushness,
   luxuriance, manner of speaking, measure, mordent, movement,
   musical phrase, musical sentence, nonliterality, nonliteralness,
   order, ornamentation, overcharge, overlay, overload, padding,
   paint, part, passage, paste on, period, phrase, plus, postfix,
   pralltriller, prank, prank up, preen, prefix, premium, prettify,
   primp, primp up, prink, prink up, purple passage, purple patches,
   put with, red ribbon, redecorate, redo, refrain, refurbish,
   resolution, response, riband, ribbon, ritornello, roulade, run,
   saddle with, section, set off, set out, single mordent, slap on,
   smarten, smarten up, something extra, spruce up, stanza, star,
   statement, strain, stuffing, subjoin, suffix, superadd,
   superaddition, superpose, tack on, tag, tag on, tailpiece,
   titivate, trick out, trick up, trim, trimming, trope, turn,
   turn of expression, tutti, tutti passage, twist, unite with,
   variation, varnish, verse, way of speaking, window dressing,
   wrinkle



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ORNAMENT. An embellishment. In questions arising as to which of two things
is to be considered as principal or accessory, it is the rule, that an
ornament shall be considered as an accessory. Vide Accessory; Principal.