(1):

(n.) A movable building, of a square form, consisting of ten or even twenty stories and sometimes one hundred and twenty cubits high, usually moved on wheels, and employed in approaching a fortified place, for carrying soldiers, engines, ladders, casting bridges, and other necessaries.

(2):

(n.) The elevated central portion of the roof of a passenger car. Its sides are pierced for light and ventilation.

(3):

(n.) A little tower, frequently a merely ornamental structure at one of the angles of a larger structure.

(4):

(n.) A revolving tower constructed of thick iron plates, within which cannon are mounted. Turrets are used on vessels of war and on land.