Also found in: Dictionary, Wikipedia.


A deep block sometimes placed above a Byzantine capital to support the wide voissoirs of an arch above; also, an isolated section of an entablature above a column.


A member or supplementary capital resting on the top of the capital of a column; see impost block; also called a double capital.

impost block, dosseret, supercapital

A transitional member, often tapered, placed above a column capital to receive the thrust of vaults or arches.