Lunette

Part of speech: noun (n.)

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

2. 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 (Arch.), a window which fills or partly fills a lunette.