Definition of captain noun from the Oxford Advanced American Dictionary
captain
noun
/ˈkæptən/
1the person in charge of a ship or commercial aircraftCaptain CookThe captain gave the order to abandon ship.Captain Jones and her copilot2an officer of fairly high rank in the navy, the army, and the U.S. air forceCaptain Lance Price3the leader of a group of people, especially a sports teamShe was captain of the hockey team at school.He has just been made team captain.4an officer of high rank in a U.S. police or fire department