Cupola
Cupola (k?"p?-l?) , noun
[Italian cupola, Late Latin cupula, cuppula (compare Latin cupula little tub). from cupa, cuppa, cup; compare Latin cupa tub. So called on account of its resemblance to a cup turned over. See Cup, and compare Cupule.]
1.
(Architecture) 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.
(Anatomy) The top of the spire of the cochlea of the ear.