1. (n.) A fieldwork consisting of two faces, forming a salient angle, and two parallel flanks. See Bastion.

2. (n.) A half horseshoe, which wants the sponge.

3. (n.) A kind of watch crystal which is more than ordinarily flattened in the center; also, a species of convexo-concave lens for spectacles.

4. (n.) A piece of felt to cover the eye of a vicious horse.

5. (n.) Any surface of semicircular or segmental form; especially, the piece of wall between the curves of a vault and its springing line.

6. (n.) An iron shoe at the end of the stock of a gun carriage.

advanced work balistraria bank banquette barbed-wire entanglement barbican barricade barrier bartizan bastion battlement breastwork bulwark casemate cheval-de-frise circumvallation contravallation counterscarp curtain demibastion dike drawbridge earthwork enclosure entanglement escarp escarpment fence fieldwork fortalice fortification glacis loophole lunette machicolation mantelet merlon mound outwork palisade parados parapet portcullis postern gate rampart ravelin redan redoubt sally port scarp sconce stockade tenaille vallation vallum work