1. A pull with the utmost effort, as in the athletic contest called tug of war; a supreme effort. At the tug he falls, Vast ruins come along, rent from the smoking walls. (Dryden)
2. A sort of vehicle, used for conveying timber and heavy articles.
3. A small, powerful steamboat used to tow vessels; called also steam tug, tugboat, and towboat.
4. A trace, or drawing strap, of a harness.
5. (Science: chemical) An iron hook of a hoisting tub, to which a tackle is affixed. Tug iron, an iron hook or button to which a tug or trace may be attached, as on the shaft of a wagon.