cupola

US /ˈkjuː.pəl.ə/
UK /ˈkjuː.pəl.ə/
"cupola" picture
1.

a small dome, especially a decorative one crowning a roof or turret.

:
•
The old building was topped with a beautiful copper cupola.
•
From the cupola, you can see the entire city.
:
dometurretlantern
2.

a rotating turret on a tank or armored vehicle, typically housing a gun.

:
•
The tank's cupola rotated to aim at the target.
•
The commander observed the battlefield from the tank's cupola.
:
turretdome