lifesaver (n.)

• attendant
• caretaker
• conservationist
• conservator
• curator
• custodian
• deliverer
• gamekeeper
• governor
• guardian
• janitor
• keeper
• lifeboat
• lifeguard
• preservationist
• preserver
• ranger
• rescuer
• saver
• savior
• shepherd
• steward
• taxidermist
• warden
• warder