One who shares an office with another

(idiomatic, colloquial) A police officer.

A peace officer who is a member of a police force.

A jailer.

(military, nautical) A naval officer with the rank of rear admiral or above. Such officers are entitled to fly a personal flag, especially on the flagship.

plural of office mate

Individual required to maintain accounting, including records thereof, of property and funds, whether public or quasi-public. The accountable officer may or may not have physical possession of the property or funds.

The times, typically from about 9am to 5pm, Monday to Friday, when non-24/7 office workers are at their desks.

A non-commissioned officer in the Canadian, US and UK Navy and the US Coast Guard; roughly equivalent to a sergeant in the army

(military) An officer holding rank by virtue of a warrant rather than a commission. / (law enforcement) An officer assigned to execute warrants and other writs.