Definitions
1.NounThe copilot of an aircraft.
2.NounThe chief mate of a merchant ship.
3.NounThe executive officer, second in command of a naval vessel.
4.NounThe most senior civil servant in the United States Foreign Service, with responsibility for running an embassy under the authority of and reporting to the ambassador.
5.NounAir Transport Auxiliary rank corresponding to Flight Lieutenant in the Royal Air Force.
6.NounWomen's Royal Naval Service rank corresponding to Lieutenant-Commander in the Royal Navy.