Definition of: tread

(tred) v. trod (Archaic trode), trod·den or trod, tread·ing v.t.
1. To step or walk on, over, along, etc.: to tread the floor.
2. To press with the feet; trample: to tread grass.
3. To accomplish in walking or in dancing: to tread a measure.
4. To copulate with: said of male birds.
—v.i.
5. To place the foot down; walk.
6. To press the ground or anything beneath the feet: usually with on.
—to tread water In swimming, to keep the body erect and the head above water by moving the feet up and down as if walking.
—noun
1. The act or manner of treading; a walking or stepping.
2. That on which something treads or rests in moving, or which affords space for or as for treading.
3. The part of a wheel that bears upon the ground or rails.
4. The outer surface of an automobile tire, or the distance between opposite wheels.
5. The part of a rail on which the wheels bear.
6. The cica-tricle or chalaza of an egg.
7. The impression made by a foot, a tire, etc.
8. The flat part of a step in stairs. [OE tredan]
—tread′er noun
—tread′ing noun