Keystone

(redirected from keystones)
Also found in: Dictionary, Thesaurus, Legal.
Related to keystones: keystone arch

keystone

[′kē‚stōn]
(architecture)
Wedge-shaped stone at the crown of an arch.
(materials)
Small crushed stone used as filler for the large aggregate in bituminous bound roads.

Keystone

The central stone or voissoir at the top of the arch, the last part to be put into position to lock the arch in place, often embellished.

Keystone

 

in architecture, the stone or brick, usually wedge-shaped, at the top of an arch or vault. Its function is usually accentuated by ornamental patterns and carvings. A decorative keystone often adorns the flat lintel over the apertures of doors or windows. [9–963–l]

keystone, key block

keystone, 1: K
1. The central voussoir of an arch, which is often embellished; until the keystone is in place, no true arch action takes