Cupola

n.	1.	(Arch.) A roof having a rounded form, hemispherical or nearly so; also, a ceiling having the same form. When on a large scale it is usually called dome.
	2.	A small structure standing on the top of a dome; a lantern.
	3.	A furnace for melting iron or other metals in large quantity, - used chiefly in foundries and steel works.
	4.	A revolving shot-proof turret for heavy ordnance.
	5.	(Anat.) The top of the spire of the cochlea of the ear.

Noun	1.	cupola - a vertical cylindrical furnace for melting iron for casting
	2.	cupola - a roof in the form of a dome

antenna tower, apse, arcade, arcature, arch, arched roof, archway, barbican, belfry, bell tower, camber, campanile, ceilinged roof, colossus, column, concameration, concha, cove, derrick, dome, fire tower, geodesic dome, igloo, keystone, lantern, lighthouse, martello, martello tower, mast, minaret, monument, obelisk, observation tower, ogive, pagoda, pilaster, pillar, pinnacle, pole, pylon, pyramid, shaft, skewback, skyscraper, span, spire, standpipe, steeple, stupa, television mast, tope, tour, tower, turret, vault, vaulting, voussoir, water tower, windmill tower