flag officer

noun

1. a naval officer above the rank of captain, as a fleet admiral, admiral, vice-admiral, rear admiral, or commodore, who is entitled to display a flag indicating his or her rank.
2. (formerly) an officer in command of a fleet, squadron, or group of ships.

noun

1. an officer in certain navies of the rank of rear admiral or above and entitled to fly its flag
2. the head of a boat or yacht club