The Collaborative International Dictionary of English v.0.48:

Caparison \Ca*par"i*son\, v. t. [imp. & p. p. Caparisonedp.
   pr. & vb. n. Caparisoning.] [Cf. F capara[,c]onner.]
   [1913 Webster]
   1. To cover with housings, as a horse; to harness or fit out
      with decorative trappings, as a horse.
      [1913 Webster]

            The steeds, caparisoned with purple, stand.
                                                  --Dryden.
      [1913 Webster]

   2. To adorn with rich dress; to dress.
      [1913 Webster]

            I am caparisoned like a man.          --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Caparison \Ca*par"i*son\, n. [F. capara[,c]on, fr. Sp. caparazon
   a cover for a saddle, coach, etc.; capa cloak, cover (fr. LL.
   capa, cf. LL. caparo also fr. capa) + the term. azon. See
   Cap.]
   1. An ornamental covering or housing for a horse; the harness
      or trappings of a horse, taken collectively, especially
      when decorative.
      [1913 Webster]

            Their horses clothed with rich caparison. --Drylen.
      [1913 Webster]

   2. Gay or rich clothing.
      [1913 Webster]

            My heart groans beneath the gay caparison.
                                                  --Smollett.
      [1913 Webster]

WordNet (r) 3.0 (2006):

caparison
    n 1: stable gear consisting of a decorated covering for a horse,
         especially (formerly) for a warhorse [syn: caparison,
         trapping, housing]
    v 1: put a caparison on; "caparison the horses for the festive
         occasion" [syn: caparison, bard, barde, dress up]