lunettes

1. A small opening in a vaulted roof of a circular or crescent shape.
2. A crescent-shaped recess or void in the space above a window or door.
3. An image or other representation of a crescent moon.
4. (fortifications) A field work consisting of two projecting faces forming a wedge each of which extends from one of two parallel flanks.
5. A luna: a crescent-shaped receptacle, often glass, for holding the (consecrated) host (the bread of communion) upright when exposed in the monstrance.
6. A type of flattened glass used in watch-making.
7. The circular hole in the guillotine in which the victim's neck is placed.
8. A type of crescent-shaped dune blown up along a lake basin, especially in dry areas of Australia.
9. A half horseshoe, lacking the sponge.
10. A piece of felt to cover the eye of a vicious horse.
11. An iron shoe at the end of the stock of a gun carriage.
12. (in the plural) See lunettes.

noun

A particular kind of spectacles/glasses, consisting of two circles lenses connected by a half-circle bridge over the nose.