1. a person who holds a position of authority in the military, police, or other organization
2. a person elected or appointed to hold an official position in a company, organization, or government

Examples

• The police officer directed traffic around the accident.
• She was promoted to the rank of lieutenant officer in the army.
• The chief executive officer announced the company’s new strategy.
• He serves as a loan officer at the local bank.
• The security officer checked everyone’s identification at the entrance.
• The naval officer commanded a destroyer in the Pacific.
• She was elected as an officer of the student council.