a person who has charge of the keys of a prison; jailer.
adjective
2.
Also, turn-key.of, pertaining to, or resulting from an arrangement under which a private contractor designs and constructs a project, building, etc., for sale when completely ready for occupancy or operation: turn-key housing, turnkey contract.
3.
fully equipped; ready to go into operation: a turnkey business.
archaic a keeper of the keys, esp in a prison; warder or jailer
—adj
2.
denoting a project, as in civil engineering, in which a single contractor has responsibility for the complete job from the start to the time of installation or occupancy