The Collaborative International Dictionary of English v.0.48:

Stockade \Stock*ade"\, n. [F. estacade stockade, boom (confused
   in French with estocade; see 1st Stoccado); fr. It.
   steccata a palisade (influenced by OF. estach, estaque, a
   stake, post), or from Sp. estacada a palisade; both of German
   origin, and akin to E. stake, stick; cf. G. stecken stick,
   OHG. steccho. See Stake, n., Stick, n. & v. t., and cf.
   Estacade, Stacket.]
   1. (Mil.) A line of stout posts or timbers set firmly in the
      earth in contact with each other (and usually with
      loopholes) to form a barrier, or defensive fortification.
      [Written also stoccade.]
      [1913 Webster]

   2. An inclosure, or pen, made with posts and stakes.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stockade \Stock*ade"\, v. t. [imp. & p. p. Stockaded; p. pr. &
   vb. n. Stockading.]
   To surround, fortify, or protect with a stockade.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stockade
    n 1: fortification consisting of a fence made of a line of stout
         posts set firmly for defense
    2: a penal camp where political prisoners or prisoners of war
       are confined (usually under harsh conditions) [syn:
       concentration camp, stockade]
    v 1: surround with a stockade in order to fortify

Moby Thesaurus II by Grady Ward, 1.0:

108 Moby Thesaurus words for "stockade":
   POW camp, abatis, advanced work, balistraria, bank, banquette,
   barbed-wire entanglement, barbican, barricade, barrier, bartizan,
   bastille, bastion, battlement, black hole, borstal,
   borstal institution, breastwork, bridewell, brig, bulwark,
   calaboose, can, casemate, cell, cheval-de-frise, circumvallation,
   concentration camp, condemned cell, contravallation, cooler, coop,
   counterscarp, curtain, death cell, death house, death row,
   demibastion, detention camp, dike, drawbridge, earthwork,
   enclosure, entanglement, escarp, escarpment, federal prison, fence,
   fieldwork, forced-labor camp, fortalice, fortification, gaol,
   glacis, guardhouse, guardroom, hoosegow, house of correction,
   house of detention, industrial school, internment camp, jail,
   jailhouse, jug, keep, labor camp, lockup, loophole, lunette,
   machicolation, mantelet, maximum-security prison, merlon,
   minimum-security prison, mound, oubliette, outwork, palisade,
   parados, parapet, pen, penal colony, penal institution,
   penal settlement, penitentiary, portcullis, postern gate, prison,
   prison camp, prisonhouse, rampart, ravelin, redan, redoubt,
   reform school, reformatory, sally port, scarp, sconce,
   sponging house, state prison, tenaille, the hole, tollbooth,
   training school, vallation, vallum, work