2. (Far.) 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. (Arch.) 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.