a small tower, usually one forming part of a larger structure.

a small tower at an angle of a building, as of a castle or fortress, frequently beginning some distance above the ground.

Also called turrethead

Military . a domelike, sometimes heavily armored structure, usually revolving horizontally, within which guns are mounted, as on a fortification, ship, or aircraft.

Fortification . a tall structure, usually moved on wheels, formerly employed in breaching or scaling a fortified place, a wall, or the like.

noun

belfry , lathe , minaret , spire , steeple , tower