or Barbican, an outer defence, or fortification to a city or castle, used especially as a fence to the city, or walls; also, an aperture made in the wall of a fortress, to fire through upon the enemy.

BARBACAN is also used to denote a fort at the entrance of a bridge, or the outlet of a city, having a double wall with towers.

BARBALIA, in botany, a genus of the didynamia angiosperma. The calyx consists of four divisions; the capsule capsule is quadrangular, with two elastic valves, and two seeds. There are six species, none of them natives of Britain.

in architecture, a canal, or opening left in the wall, for water to come in and go out, when buildings are erected in places liable to be overflowed, or to drain off the water from a terras, or the like.