A person who has a commission or warrant to perform some office, or execute some business, for the government, corporation, or person employing him; as, a commissioner to take affidavits or to adjust claims.
- A member of a commission.
- A person authorized by a commission to perform certain duties.
- A governmental official in charge of a department: a police commissioner.
- Sports An official selected by an athletic association or league to exercise administrative or regulatory powers over it: a baseball commissioner.