refectory: A dining room in a monastery.

Other parts of monastery: chapter house, cloister, scriptorium.

relieving arch: An arch which encloses an arch or a window or other opening. It helps relieve some of the weight on the arch of the opening.

Compare with blind arch

reliquary: A container for relics. Often reliquaries were in the form of caskets, though it was quite common for them to be shaped like statues or body parts (such as hands or heads).

Compare with:monstrance.

retable: An altarpiece, decorated with painting or sculpture which stands at the back of an altar.

rib: An arch of masonry, often molded, which forms part of the framework on which a vault rests. Ribs generally project from the undersurface of the vault.

See also rib vault
Types of ribs: diagonal rib, lierne, ridge rib, tierceron, transverse rib
Compare with infilling or webbing

rib vault: A masonry vault with a relatively thin web and set within a framework of ribs.

Types of rib vaults: fan, net, quadripartite, sexpartite
Compare with: barrel or tunnel vault, groin vault

ridge rib or longitudinal ridge rib: A rib which runs down the apex of the vault in a longitudinal direction.

Other types of ribs:diagonal, lierne, tierceron, transverse rib.
See also rib vault

rise (of an arch or a vault): The vertical distance between the spring line of an arch or vault and the keystone or boss.

See also boss, keystone, span, spring line.

rose window: A circular window composed of patterned tracery arranged in petal-like formation.

Compare with lancet window.