commissioner

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A member of a commission.
• noun A person authorized by a commission to perform certain duties.
• noun A governmental official in charge of a department.
• noun Sports An official selected by an athletic association or league to exercise administrative or regulatory powers over it.

from The Century Dictionary.

• noun A betting-broker at a race-track.
• noun One who commissions.
• noun A person having or included in a warrant of authority; one who has a commission or warrant from proper authority to perform some office or execute some business for the person, court, or government giving the commission.
• noun Specifically— In Great Britain, an officer having charge of some department of the public service which is put into commission. See to put in commission, under commission, n.
• noun A steward or private factor on an estate, who holds a power from his constituent to manage affairs with full authority.
• noun A commissionaire.
• noun One of the persons elected to manage the affairs of a police burgh or non-corporate town in Scotland, corresponding to a bailie or town-councilor in a corporate town.

from the GNU version of the Collaborative International Dictionary of English.

• noun A person who has a commission or warrant to perform some office, or execute some business, for the government, corporation, or person employing him.
• noun An officer having charge of some department or bureau of the public service.
• noun [U. S.] an officer having authority to take affidavits, depositions, acknowledgment of deeds, etc., for use in the State by which he is appointed.
• noun [U. S.] certain administrative officers in some of the States, invested by local laws with various powers in reference to the roads, courthouses, financial matters, etc., of the county.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A member of a commission.
• noun Someone commissioned to perform certain duties.
• noun An official in charge of a government department, especially a police force.
• noun Someone who commissions something

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a government administrator
• noun a member of a commission