Turret

·noun A little tower, frequently a merely ornamental structure at one of the angles of a larger structure.

II. Turret ·noun The elevated central portion of the roof of a passenger car. Its sides are pierced for light and ventilation.

III. Turret ·noun A revolving tower constructed of thick iron plates, within which cannon are mounted. Turrets are used on vessels of war and on land.

IV. Turret ·noun 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.