A work projecting outward from the main inclosure of a
fortification, consisting of two faces and two flanks, and so
constructed that it is able to defend by a flanking fire the adjacent
curtain, or wall which extends from one bastion to another. Two
adjacent bastions are connected by the curtain, which joins the flank
of one with the adjacent flank of the other. The distance between the
flanks of a bastion is called the gorge. A lunette is a detached
bastion. See Ravelin.