n. In architecture, a vault, either hemispherical or produced by the revolution about its axis of two curves intersecting at the apex, or by a semi-ellipse covering a circular or polygonal area, and supported either upon four arches or upon solid walls.n. The round top of any structure, as of a furnace; the structure itself. See cupola-furnace. Specificallyn. Milit., a revolving shot-proof turret, formed of strong timbers, and armored with massive iron plates.n. In anatomy: The summit of the cochlea. The summit of an intestinal gland.n. In conchology, the so-called dorsal or visceral hump, made by the heap of viscera.