Indentured is the adjective (and the past form of the verb): bound by an indenture. An indentured apprentice or indentured servant has been tied, by that formal contract, to work for a master for a set time. History books speak of indentured labour — people who were not free until the years ran out. Some went of their own will, hoping for land or a trade at the end; some were pushed by debt or hunger; some were tricked. Though actually, ending the contract did not always mean a fair new life, which is why the word still carries a chill. You almost never use it for a modern job. We say someone is on a contract, or in a fixed-term post. Indentured belongs to the old papers, and to that half-free, half-owned state they created.