The Collaborative International Dictionary of English v.0.48:

Festoon \Fes*toon"\, n. [F. feston (cf. Sp. feston, It.
   festone), prob. fr. L. festum festival. See Feast.]
   1. A garland or wreath hanging in a depending curve, used in
      decoration for festivals, etc.; anything arranged in this
      way.
      [1913 Webster]

   2. (Arch. & Sculp.) A carved ornament consisting of flowers,
      and leaves, intermixed or twisted together, wound with a
      ribbon, and hanging or depending in a natural curve. See
      Illust. of Bucranium.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Festoon \Fes*toon"\, v. t. [imp. & p. p. Festooned; p. pr. &
   vb. n. Festooning.]
   To form in festoons, or to adorn with festoons.
   [1913 Webster]

WordNet (r) 3.0 (2006):

festoon
    n 1: a curtain of fabric draped and bound at intervals to form
         graceful curves
    2: an embellishment consisting of a decorative representation of
       a string of flowers suspended between two points; used on
       pottery or in architectural work
    3: flower chains suspended in curves between points as a
       decoration [syn: festoon, festoonery]
    v 1: decorate with strings of flowers; "The public buildings
         were festooned for the holiday"

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "festoon":
   arc, boughpot, bouquet, boutonniere, bow, bravery, buttonhole,
   catacaustic, catenary, caustic, chaplet, chiffon, circle,
   clinquant, conchoid, corsage, crook, curl, curve, diacaustic,
   ellipse, festoons, finery, flower arrangement, folderol, foofaraw,
   frilliness, frilling, frills, frills and furbelows, frippery,
   froufrou, fuss, gaiety, garland, gaudery, gilding, gilt,
   gingerbread, hook, hyperbola, lei, lituus, nosegay, parabola,
   paste, pinchbeck, posy, sinus, spray, superfluity, tinsel, tracery,
   trappings, trickery, trumpery, wreath