master at arms
/ˈmæstər ət ˈɑrmz/
noun
- A person responsible for keeping order and enforcing rules on a ship or in a military unit.
- When a fight broke out in the mess hall, the master-at-arms quickly intervened.
- The master-at-arms patrolled the ship's corridors to make sure everyone followed the rules.
- The new recruits learned to respect the master-at-arms, who maintained discipline on the base.