n.系绳；系链；界限；（能力、财力、忍耐等的）极限
v.练栓；拘束
The astronauts walked in outer space without a tether. 宇航员在没有系绳的情况下进行太空行走。
This group is composed of men who had never associated themselves with rickshaws but were forced to take up the trade, because they have reached the end of their tether. 这一些是以前决没想到自己能与洋车发生关系，而到了生和死的界限已经不甚分明，才抄起车把来的。
