turret

plural turrets

1. architectureA little tower, frequently a merely ornamental structure at one of the corners of a building or castle.

   Their Victorian house had three turrets and a large amount of gingerbread trim.

   2 more examples

   There breathes no being but has some pretence / To that fine instinct called poetic sense; […] / The freeman, casting with unpurchased hand / The vote that shakes the turrets of the land.

   1836, Oliver Wendell Holmes, Sr., “Poetry: A Metrical Essay”, republished in The Poems of Oliver Wendell Holmes, Boston, Mass.: Ticknor and Fields, 1862, OCLC 5091562, pages 7–8

   Awake! for Morning in the Bowl of Night, Has flung the Stone that puts the Stars to Flight: And Lo! the Hunter of the East has caught The Sultán's Turret in a Noose of light.

   1859, Edward Fitzgerald, The Rubáiyát of Omar Khayyám: The Astronomer-Poet of Persia, page 1

2. historicalgovernmentA siege tower; 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. businessA tower-like solder post on a turret board (a circuit board with posts instead of holes).
4. governmentAn armoured, rotating gun installation on a fort, ship, aircraft, or armoured fighting vehicle.
5. rail transportThe elevated central portion of the roof of a passenger car, with sides that are pierced for light and ventilation.
6. businessA turret head.
7. gamblingThe central conical ornament atop a spinning roulette wheel.