cupola
n
1 a roof or ceiling in the form of a dome
2 a small structure, usually domed, on the top of a roof or dome
3 a protective dome for a gun on a warship
4 a vertical air-blown coke-fired cylindrical furnace in which iron is remelted for casting
(C16: from Italian, from Late Latin cupula a small cask, from Latin cupa tub)
♦
cupolated adj