| commanding officer |
a military officer in charge of a unit or installation. |
| commissioned officer |
a military or naval officer holding a rank by commission. |
| executive officer |
in the military, an officer who is assistant to the commanding officer of a unit, or who is second in command of a unit smaller than a division. [2 definitions] |
| field officer |
a military officer with the rank of colonel, lieutenant colonel, or major. |
| flag officer |
a naval or coast guard officer above the rank of captain, who is entitled to have a special flag displayed when he or she is aboard ship. |
| general officer |
any military officer who ranks above colonel. |
| noncommissioned officer |
an enlisted member of the armed forces with an officer's rank below commissioned or warrant officers, such as a sergeant or corporal in the U.S. Army. |
| officer of the day |
a military officer assigned, on a given day, to maintain the security and order of a military post or installation. |
| petty officer |
a noncommissioned naval officer. |
| police officer |
a person who is a member of a police force. |
| probation officer |
a court-appointed official who supervises persons, including convicts, who are on probation. |
| staff officer |
a commissioned military officer who serves on a staff. [2 definitions] |
| truant officer |
a school official who investigates students' unauthorized absences. |
| warrant officer |
an officer in the U.S. armed forces that ranks above noncommissioned officers and below commissioned officers and holds office on a warrant instead of a commission. |