tether
/ˈteðə(r); `tɛðɚ/ n
1 rope or chain by which an animal is fastened while it is grazing （拴牲畜的）绳或链.
2 (idm 习语) at the end of one's tether => end1. tether, v [Tn, Tn.pr]
~ sth (to sth) fasten (an animal) with a tether 用绳或链拴住（牲畜）
He tethered his horse to a tree. 他用绳子把马拴在树上.