- A fieldwork consisting of two faces, forming a salient
angle, and two parallel flanks. See Bastion. - A half horseshoe, which wants the sponge. - A kind of watch crystal which is more than ordinarily
flattened in the center; also, a species of convexoconcave lens for
spectacles. - A piece of felt to cover the eye of a vicious horse. - Any surface of semicircular or segmental form; especially,
the piece of wall between the curves of a vault and its springing line. - An iron shoe at the end of the stock of a gun carriage.