--noun (singular: officer; plural: officers)

1. military officer: any person in the armed services who holds a position of authority or command.
  • "An officer is responsible for the lives of his men."
2. officeholder: someone who is appointed or elected to an office and who holds a position of trust.
  • "He is an officer of the court."
3. police officer: a member of a police force.
  • "It was an accident, officer."
4. ship's officer: a person authorized to serve in a position of authority on a vessel.
  • "He is the officer in charge of the ship's engines."

--verb

5. to direct or command as an officer.

An officer is a person who has a position of authority in a hierarchical organization. The term derives from the late Latin from officiarius, meaning "official".