architecture, that part of a column which lies immediately upon the capital, being the lowest member of the entablature.

Over a chimney, this member is called the mantel-piece; and over doors or windows, the hyperthyron.

Archivault, in architecture, implies the inner contour of an arch, or a band adorned with mouldings, running over the faces of the arch-flutes, and bearing upon the impost. It has only a single face in the Tuscan order, two faces crowned in the Doric and Ionic, and the same mouldings as the architrave in the Corinthian and Composite.