lunette

noun11

1. •
   A small opening in a vaulted roof of a circular or crescent shape.

   • Nanny Broome was looking up at the outer wall. Just under the ceiling there were three lunette windows, heavily barred and blacked out in the normal way by centuries of grime. — 1963
2. •
   A crescent-shaped recess or void in the space above a window or door.
3. •
   The circular hole in the guillotine in which the victim's neck is placed.
4. •
   A type of crescent-shaped dune blown up along a lake basin, especially in dry areas of Australia.

   • Sticking out of a crescent-shaped sand ridge of a type known as a lunette were some human bones. — 2003
5. •
   A field work consisting of two projecting faces forming a wedge each of which extends from one of two parallel flanks.

   • This Lunette, as we have seen, was confronted, and even in siege-form "approached", by a part of Canrobert's army [...]. — 1863
6. •
   A luna: a crescent-shaped receptacle, often glass, for holding the (consecrated) host (the bread of communion) upright when exposed in the monstrance.
7. •
   A type of flattened glass used in watch-making.

   • Lunette and double lunette glasses are generally sized in quarters; crystals and thin flat lunettes for hunters in eighths. — 2008
8. •
   A half horseshoe, lacking the sponge.
9. •
   A piece of felt to cover the eye of a vicious horse.
10. •
    An iron shoe at the end of the stock of a gun carriage.
11. •
    (no longer used) An image or other representation of a crescent moon.