Other forms: voussoirs
A voussoir is a wedge-shaped stone used in building arches and vaults. If you’re building an arch, or any other curved shape, rectangle bricks just won’t do. You need a voussoir or two!
One type of building block is named by the French word voussoir. A voussoir is a stone block that’s wedge shaped, like a piece of pie with a bite taken out. Since it takes more than one to build with, the word is usually plural. Voussoirs are used to make specific buildings — arches and tombs. The rounded form of an arch is tricky to build, and the wedge shape of voussoirs helps them fit together.