The Oxford Thesaurus An A-Z Dictionary of Synonyms - tethern.

1) lead, leash, rope, cord, fetter, restraint, halter, tie, chain: The dog had broken loose from its tether and was running around in the yard. --v. 2) tie (up or down) , restraint, fetter, chain (up or down) , leash, manacle, secure, shackle, fasten, picket, stake: Why don't you tether the goat where the grass is more plentiful?