turret

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A small tower or tower-shaped projection on a building.
2. n. A low, heavily armored structure, usually rotating horizontally, containing mounted guns and their gunners or crew, as on a warship or tank.
3. n. A domelike gunner's enclosure projecting from the fuselage of a combat aircraft.
4. n. A tall wooden structure mounted on wheels and used in ancient warfare by besiegers to scale the walls of an enemy fortress.
5. n. An attachment for a lathe consisting of a rotating cylindrical block holding various cutting tools.
6. n. A rotating device holding various lenses, as for a microscope, allowing easy switching from one lens to another.

Century Dictionary and Cyclopedia

1. n. An attachment to a lathe, drill, boring-machine, or slotting-machine designed to hold and present to the work a series of boring-, drilling-, or cutting-tools, the object being to save the time lost in changing from one tool to another by hand. In a lathe it consists of a round or six- or eight-sided horizontal tool-holder placed between the two heads. It has a circular motion in a horizontal 'plane, or may have a tilting circular motion that may be controlled by hand or may be automatic, and may also have a feed-motion to advance the tool to the work. The presentation of one tool to the work, the feed, the withdrawal of the tool on the completion of the cutting, and the partial revolution of the turret to bring another tool into action, may be automatic and continuous. In the boring-mill the turret is suspended over the table on a horizontal axis. In the slotting-machine it may be carried on the cutter-head, moving with n. It may carry four cutters, each of which may be brought into use in turn. In the drill the turret is suspended on a horizontal axis and may carry six drills, each one of which may be brought into action in turn by revolving the tuitet, the drills not at work remaining motionless. The turret gives its name to the machine in which it is employed, as a turret-lathe, a turret boring-machine, etc. Machines employing turrets are usually automatic and perform a complete series of operations on the work, as in a screw-machine or screw-cutting machine or the turret forming-machine. A turret is sometimes called a monitor from its shape.
2. n. A little tower rising from or otherwise connected with a larger building; a small tower, often crowning or finishing the angle of a wall, etc. Turrets are of two chief classes—such as rise immediately from the ground, as staircase turrets, and such as are formed on the upper parts of a building, often corbeled out from the wall and not extending down to the ground, as bartizan turrets. See also cuts under peel and bartizan.
3. n. In medieval warfare, a movable building of a square form, consisting of ten or even twenty stories, and sometimes 180 feet high, usually moved on wheels, and employed in approaches to a fortified place for carrying soldiers, engines, ladders, etc.
4. n. Milit., a tower, often revolving, for offensive purposes, on land or water. See cut under monitor.
5. n. In her.: A small slender tower, usually forming part of a bearing, being set upon a larger tower. Sec turreted, 3.
6. n. A bearing representing a kind of scepter having both ends alike and resembling the ends of the cross avellane. See tirret.
7. n. In a railroad-car of American model, the raised part of the middle of the roof, utilized for affording light and ventilation.
8. n. In a lathe, a cylindrical or polygonal block on the bed, with holes around it for dies.
9. n. Same as terret.

Wiktionary

1. n. architecture a little tower, frequently a merely ornamental structure at one of the corners of a building or castle
2. n. historical, military a 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. n. military an armoured, rotating gun installation, on a fort, ship, aircraft, or armoured fighting vehicle
4. n. rail transport the elevated central portion of the roof of a passenger car. Its sides are pierced for light and ventilation
5. n. electronics a tower-like solder post on a turret board (a circuit board with posts instead of holes)

GNU Webster's 1913

1. n. (Arch.) A little tower, frequently a merely ornamental structure at one of the angles of a larger structure.
2. n. (Anc. Mil.) 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. n. (Mil.) A revolving tower constructed of thick iron plates, within which cannon are mounted. Turrets are used on vessels of war and on land.
4. n. (Railroads) The elevated central portion of the roof of a passenger car. Its sides are pierced for light and ventilation.

WordNet 3.0

1. n. a self-contained weapons platform housing guns and capable of rotation
2. n. a small tower extending above a building