1. 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. A truck having a cab and no body, used for pulling large vehicles such as vans or trailers.
3. Something that pulls or draws.
4. 1. An airplane propeller mounted in front of the supporting surfaces.
   2. An airplane having such a propeller.
5. A toothed mechanism that automatically advances perforated continuous-form paper through a computer printer.

[From Latin tractus, past participle of trahere, to draw.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.