turret
n. countablen. a small tower on top of a larger tower or at the corner of a building. It can also mean the part of a tank or ship that holds a large gun and turns around.
n. a small tower projecting from a corner or wall of a building, or a rotating armoured structure on a vehicle or ship that houses weaponry. Often used in architectural and military contexts.
The castle has a small turret on each corner.
The tank commander rotated the turret to face the target while the driver moved into position.
From the narrow windows of the stone turret, the guards could see for miles across the valley, ensuring no one approached the fortress unnoticed.
From Middle English touret, from Old French torete (French tourette), diminutive of tour (“tower”), from Latin turris. Doublet of tor, tourelle, and tower. See tower.
In military contexts, it refers specifically to the rotating part of the vehicle; in architecture, it refers to a fixed structure.