Etymology

Noun

1. A little tower, frequently a merely ornamental structure at one of the corners of a building or castle.
2. 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.
3. An armoured, rotating gun installation, on a fort, ship, aircraft, or armoured fighting vehicle.
4. The elevated central portion of the roof of a passenger car. Its sides are pierced for light and ventilation.