(1):

(a.) A body of men intrusted with vicarious government; as, a regency constituted during a king's minority, absence from the kingdom, or other disability.

(2):

(a.) The office of ruler; rule; authority; government.

(3):

(a.) Especially, the office, jurisdiction, or dominion of a regent or vicarious ruler, or of a body of regents; deputed or vicarious government.