1. A fieldwork consisting of two faces, forming a salient angle, and two parallel flanks. See Bastion.
2. (Science: veterinary) a half horseshoe, which wants the sponge.
3. A kind of watch crystal which is more than ordinarily flattened in the center; also, a species of convexoconcave lens for spectacles.
4. A piece of felt to cover the eye of a vicious horse.
5. Any surface of semicircular or segmental form; especially, the piece of wall between the curves of a vault and its springing line.
6. An iron shoe at the end of the stock of a gun carriage. Lunette window, a window which fills or partly fills a lunette.
Origin: f, dim. Of lune moon, L.luna. See lune a crescent.