Barbican

barbican
    n 1: a tower that is part of a defensive structure (such as a
         castle) [syn: {barbican}, {barbacan}]
    

Barbican \Bar"bi*can\, Barbacan \Bar"ba*can\, n. [OE. barbican,
   barbecan, F. barbacane, LL. barbacana, barbicana, of
   uncertain origin: cf. Ar. barbakh aqueduct, sewer. F.
   barbacane also means, an opening to let out water, loophole.]
   1. (Fort.) A tower or advanced work defending the entrance to
      a castle or city, as at a gate or bridge. It was often
      large and strong, having a ditch and drawbridge of its
      own.
      [1913 Webster]

   2. An opening in the wall of a fortress, through which
      missiles were discharged upon an enemy.
      [1913 Webster] Barbicanage
    

BARBICAN. An ancient word to signify a watch-tower. Barbicanage was money 
given for the support of a barbican. 
    

95 Moby Thesaurus words for "barbican":
      abatis, advanced work, antenna tower, balistraria, bank, banquette,
      barbed-wire entanglement, barricade, barrier, bartizan, bastion,
      battlement, belfry, bell tower, breastwork, bulwark, campanile,
      casemate, cheval-de-frise, circumvallation, colossus, column,
      contravallation, counterscarp, cupola, curtain, demibastion,
      derrick, dike, dome, drawbridge, earthwork, enclosure,
      entanglement, escarp, escarpment, fence, fieldwork, fire tower,
      fortalice, fortification, glacis, lantern, lighthouse, loophole,
      lunette, machicolation, mantelet, martello, martello tower, mast,
      merlon, minaret, monument, mound, obelisk, observation tower,
      outwork, pagoda, palisade, parados, parapet, pilaster, pillar,
      pinnacle, pole, portcullis, postern gate, pylon, pyramid, rampart,
      ravelin, redan, redoubt, sally port, scarp, sconce, shaft,
      skyscraper, spire, standpipe, steeple, stockade, stupa,
      television mast, tenaille, tope, tour, tower, turret, vallation,
      vallum, water tower, windmill tower, work