Source : Webster's Revised Unabridged Dictionary (1913)

Cupola \Cu"po*la\ (k?"p?-l?), n.; pl. {Cupolas} (-l?z). [It.
   cupola, LL. cupula, cuppula (cf. L. cupula little tub). fr.
   cupa, cuppa, cup; cf. L. cupa tub. So called on account of
   its resemblance to a cup turned over. See {Cup}, and cf.
   {Cupule}.]
   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.