tractor

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A vehicle having a powerful gasoline or diesel motor and usually large, heavily treaded rear tires, used especially for pulling farm implements or machinery.
2. n. A truck having a cab and no body, used for pulling large vehicles such as vans or trailers.
3. n. Something that pulls or draws.
4. n. An airplane propeller mounted in front of the supporting surfaces.
5. n. An airplane having such a propeller.
6. n. A toothed mechanism that automatically advances perforated continuous-form paper through a computer printer.

Century Dictionary and Cyclopedia

1. n. A traction-engine for use on streets and highways. Such tractors may be used to drag loaded vehicles, to drag plows in a gang, or to haul artillery-wagons and fieldpieces.
2. n. The frame and steel rope by which a gang of plows is drawn across a field by a tractionengine.
3. n. That which draws or is used for drawing; specifically, in the plural, metallic tractors. See the phrase.

Wiktionary

1. n. A vehicle used in farms e.g. for pulling farm equipment and preparing the fields.
2. n. A truck (or lorry) for pulling a semi-trailer or trailer.
3. n. Any piece of machinery that pulls something.
4. n. An airplane where the propeller is located in front of the fuselage

GNU Webster's 1913

1. n. That which draws, or is used for drawing.
2. n. Two small, pointed rods of metal, formerly used in the treatment called Perkinism.
3. n. a motor vehicle with a powerful engine and large wheels, used to pull farm equipment such as plows, harvesting machinery, etc., over farm land. Smaller forms of farm tractor are completely open, with only a seat for the driver.
4. n. a motor vehicle with a driver's cab and a powerful engine, fitted with a coupling at the rear, and designed to pull a large trailer or semi-trailer on the open highway; -- called also truck tractor. The combination of such a tractor with its trailer is called a tractor-trailer, and is a common form of truck used for commercial shipping of freight.
5. n. A propeller screw placed in front of the supporting planes of an aëroplane instead of behind them, so that it exerts a pull instead of a push; -- called also Tractor screw and Tractor propeller.
6. n. An airplane having one or more tractor propellers; -- called also tractor airplane.

WordNet 3.0

1. n. a wheeled vehicle with large wheels; used in farming and other applications
2. n. a truck that has a cab but no body; used for pulling large trailers or vans