1. (n.) One who holds an office; a person lawfully invested with an office, whether civil, military, or ecclesiastical; as, a church officer; a police officer; a staff officer.

2. (n.) Specifically, a commissioned officer, in distinction from a warrant officer.

3. (v. t.) To furnish with officers; to appoint officers over.

4. (v. t.) To command as an officer; as, veterans from old regiments officered the recruits.