tread
英 [tred]
美[trɛd]
	    - n. 踏;胎面;步态;鞋底;踏板;梯级
 - vt. 踏;踩;践踏;跳;踩出
 - vi. 踏;踩;行走;交尾
 
英英释意
- 1. a step in walking or running
 
- 2. the grooved surface of a pneumatic tire
 
- 3. the part (as of a wheel or shoe) that makes contact with the ground
 
- 4. structural member consisting of the horizontal part of a stair or step