A groin vault reinforced by ribs, one in which the intersections of the surfaces are marked by projecting bands of stone that form arches.
A masonry vault with a relatively thin web and set within a framework of ribs.
A rib vault or ribbed vault is any vault reinforced by masonry ribs. A rib vault may be a quadripartite rib vault (which is divided into four sections by two diagonal ribs) and a sexpartite rib vault (a rib vault whose surface is divided into six sections by three ribs).