The Collaborative International Dictionary of English v.0.48:

Barricade \Bar`ri*cade"\, n. [F. barricade, fr. Sp. barricada,
   orig. a barring up with casks; fr. barrica cask, perh. fr.
   LL. barra bar. See Bar, n., and cf. Barrel, n.]
   [1913 Webster]
   1. (Mil.) A fortification, made in haste, of trees, earth,
      palisades, wagons, or anything that will obstruct the
      progress or attack of an enemy. It is usually an
      obstruction formed in streets to block an enemy's access.
      [1913 Webster]

   2. Any bar, obstruction, or means of defense.
      [1913 Webster]

            Such a barricade as would greatly annoy, or
            absolutely stop, the currents of the atmosphere.
                                                  --Derham.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Barricade \Bar`ri*cade"\, v. t. [imp. & p. p. Barricaded; p.
   pr. & vb. n. Barricading.] [Cf. F. barricader. See
   Barricade, n.]
   To fortify or close with a barricade or with barricades; to
   stop up, as a passage; to obstruct; as, the workmen
   barricaded the streets of Paris.
   [1913 Webster]

         The further end whereof [a bridge] was barricaded with
         barrels.                                 --Hakluyt.
   [1913 Webster]

WordNet (r) 3.0 (2006):

barricade
    n 1: a barrier set up by police to stop traffic on a street or
         road in order to catch a fugitive or inspect traffic etc.
         [syn: roadblock, barricade]
    2: a barrier (usually thrown up hastily) to impede the advance
       of an enemy; "they stormed the barricade"
    v 1: render unsuitable for passage; "block the way"; "barricade
         the streets"; "stop the busy road" [syn: barricade,
         block, blockade, stop, block off, block up,
         bar]
    2: prevent access to by barricading; "The street where the
       President lives is always barricaded"
    3: block off with barricades [syn: barricade, barricado]

Moby Thesaurus II by Grady Ward, 1.0:

134 Moby Thesaurus words for "barricade":
   abatis, advanced work, arm, armor, armor-plate, balistraria, bang,
   bank, banquette, bar, barbed-wire entanglement, barbican, barrier,
   bartizan, bastion, batten, batten down, battle, battlement,
   blank wall, block, block up, blockade, bolt, breastwork, bulwark,
   button, button up, casemate, castellate, cheval-de-frise, chock,
   choke, choke off, circumvallation, clap, close, close off,
   close tight, close up, constrict, contain, contract,
   contravallation, counterscarp, cover, crenellate, crowd, curtain,
   debar, demibastion, dig in, dike, dog, drawbridge, earthwork,
   embattle, enclosure, entanglement, entrench, escarp, escarpment,
   fasten, fence, fieldwork, fold, fold up, fortalice, fortification,
   fortify, garrison, glacis, jam, key, latch, lock, lock out,
   lock up, loophole, lunette, machicolation, man, man the garrison,
   mantelet, merlon, mine, mound, obstruct, occlude, outwork, pack,
   padlock, palisade, parados, parapet, plumb, portcullis,
   postern gate, rampart, ravelin, redan, redoubt, roadblock,
   sally port, scarp, sconce, seal, seal off, seal up, secure, shut,
   shut off, shut out, shut the door, shut tight, shut up, slam, snap,
   squeeze, squeeze shut, stifle, stockade, stop, stop up, strangle,
   strangulate, suffocate, tenaille, vallation, vallum, wall, work,
   zip up, zipper