n.
1.
1. The act, manner, or sound of treading.
2. An instance of treading; a step.
3. A mark made by treading, as in snow.
2. The upper horizontal part of a step in a staircase.
3.
1. The part of a wheel or tire that makes contact with the road or rails.
2. The grooved face of a tire.
4. The part of a shoe sole that touches the ground.
5. Either of the continuous metal belts with which bulldozers, tanks, and certain other vehicles move over the ground.