| 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. |
| flag officer n. An officer in the navy or coast guard holding a rank higher than captain, such as rear admiral, vice admiral, or admiral. |