The Collaborative International Dictionary of English v.0.48:

Bar \Bar\ (b[aum]r), v. t. [imp. & p. p. Barred (b[aum]rd); p.
   pr. & vb. n. Barring.] [ F. barrer. See Bar, n.]
   1. To fasten with a bar; as, to bar a door or gate.
      [1913 Webster]

   2. To restrict or confine, as if by a bar; to hinder; to
      obstruct; to prevent; to prohibit; as, to bar the entrance
      of evil; distance bars our intercourse; the statute bars
      my right; the right is barred by time; a release bars the
      plaintiff's recovery; -- sometimes with up.
      [1913 Webster]

            He barely looked the idea in the face, and hastened
            to bar it in its dungeon.             --Hawthorne.
      [1913 Webster]

   3. To except; to exclude by exception.
      [1913 Webster]

            Nay, but I bar to-night: you shall not gauge me
            By what we do to-night.               --Shak.
      [1913 Webster]

   4. To cross with one or more stripes or lines.
      [1913 Webster]

            For the sake of distinguishing the feet more
            clearly, I have barred them singly.   --Burney.
      [1913 Webster]

WordNet (r) 3.0 (2006):

barred
    adj 1: preventing entry or exit or a course of action; "a
           barricaded street"; "barred doors"; "the blockaded
           harbor" [syn: barricaded, barred, blockaded]
    2: marked with stripes or bands

Moby Thesaurus II by Grady Ward, 1.0:

130 Moby Thesaurus words for "barred":
   absurd, banded, banned, beleaguered, beset, besieged, blockaded,
   bound, brinded, brindle, brindled, cabined, caged, cancellated,
   cloistered, closed-in, closed-out, confined, contraband,
   contrary to reason, cooped, cordoned, cordoned off, corralled,
   cramped, cribbed, crossbarred, debarred, deported, ejected,
   enclosed, excluded, exiled, expelled, fenced, filigreed, forbade,
   forbid, forbidden, grated, gridded, hedged, hemmed, hopeless,
   illegal, illicit, immured, impossible, imprisoned, incarcerated,
   inconceivable, jailed, laced, lacelike, lacy, latticelike,
   leaguered, left out, liquidated, listed, logically impossible,
   marbled, marbleized, meshed, meshy, mewed, mullioned, netlike,
   netted, netty, nonpermissible, not in it, not included,
   not permitted, not possible, off limits, out of bounds, outlawed,
   oxymoronic, paled, paradoxical, penned, pent-up, plexiform,
   precluded, preposterous, prohibited, purged, quarantined, railed,
   restrained, reticular, reticulate, reticulated, retiform,
   ridiculous, ruled out, ruled-out, self-contradictory, shut out,
   shut-in, streaked, streaky, striatal, striate, striated, strigate,
   strigose, striolate, striped, stripy, tabby, taboo, tabooed,
   unallowed, unauthorized, under the ban, unimaginable, unlawful,
   unlicensed, unpermissible, unsanctioned, unthinkable, untouchable,
   veined, verboten, vetoed, walled, walled-in, watered