Cupola

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.

A small structure standing on the top of a dome; a lantern.

A furnace for melting iron or other metals in large quantity, -- used chiefly in foundries and steel works.

A revolving shot-proof turret for heavy ordnance.

The top of the spire of the cochlea of the ear.