Officer (noun)

1. A person holding a position of authority in an organization, such as a business, government, or military force.
2. A person appointed or elected to a position of responsibility or authority in an organization, such as a board of directors or a club.

Origin:

Middle english: from old french officeier, from latin officiarius, from officium "duty, function".

Examples:

1. The company's officers are elected annually by the board of directors.
2. He was a commissioned officer in the army.
3. The police officer was on patrol when he saw the accident.
4. The officer in charge of the operation gave the order to proceed.
5. The new officer was sworn in at the city council meeting.