co-captain
nounUK /ˌkəʊˈkæptɪn/
US /ˌkoʊˈkæptɪn/
A co-captain is a person who leads a team together with another leader.
She was named co-captain of the soccer team this year.
OTHER MEANINGS
2. To serve as one of two or more leaders of a team or group.
He co-captained the debate club for two seasons.
3. A person who shares the role of captain on a ship or aircraft.
The co-captain checked the flight plan before takeoff.
4. One of two students who jointly lead a school team or club.
The co-captains organized practice every Friday.