indenture

indenture
v [Tn, Tn.pr]
~ sb (to sb) contract sb to work as an apprentice 与某人签订师徒合同将之收为学徒
    His son was indentured to the local blacksmith. 他的儿子拜当地的铁匠为师签订了师徒合同.

牛津英汉双解词典