A chief; one who has supreme authority; a leader; the chief officer of an army, or of any division of it.
- A person who commands, especially a commanding officer.
- A commissioned rank in the U.S. Navy or Coast Guard that is above lieutenant commander and below captain.
- One who holds this rank.
- The chief commissioned officer of a military unit regardless of his or her rank.
- An officer in some knightly or fraternal orders.