cupola
cu.po.la \'kyu:-p*-l*, -.lo-\ n [It, fr. L cupula, dim. of cupa tub] 1a: a rounded vault resting on a circular or other base and forming a roof or a ceiling 1b: a small structure built on top of a roof 2: a vertical cylindrical furnace for melting iron in the foundry having tu yeres and tapping spouts near the bottom