noun
mutineer
myoo-tuh-NEER/ˌmjuːtəˈnɪr/
A person who joins a rebellion against those in command, especially aboard a ship.
The mutineer refuses the captain's orders and joins the rebellious crew.

Etymology
French mutinier names a rebel. In English, that idea specifically concerns resistance within a command structure: soldiers or sailors openly defying their officers.
In context
mutineer chippy mcNeish was also an unlikely choice plagued by rheumatism [Music] but Shackleton counted on the rebellious carpenter
More examples
- The captain orders the mutineers to lay down their weapons.
- Soldiers arrest a mutineer who urges the unit to disobey orders.
- Each mutineer faces a trial for rebelling against the officers.
Forms
mutineer · mutineers
mutiny noun — Rebellion against authority by those under command.
mutinous adjective — Rebellious against those who are in command.