Quarry Ornament, any ornament covering a surface with two series of reticulated lines enclosing approximately quadrangular spaces or meshes.
Quatrefoil, with four leaves or foils; composed of four arcs of circles meeting in cusps pointing inward.
Quoins, slightly projecting blocks of stone, alternately long and short, decorating or strengthening a corner or angle of a façade.
Revetment, a veneering or sheathing.
Rustication, treatment of the masonry with blocks having roughly broken faces, or with deeply grooved or bevelled joints.
Soffit, the under-side of an architrave, beam, arch, or corona.
Spandril, the triangular wall-space between two contiguous arches.
Squinch, a bit of conical vaulting filling in the angles of a square so as to provide an octagonal or circular base for a dome or lantern.
Stoa, an open colonnade for public resort.
Tepidarium, the hot-water hall or chamber of a Roman bath.