A system of government that substitutes for the reign of a king or queen when that king or queen becomes unable to rule. / The time during which a regent is in power.

(historical) The regency of George Augustus Frederick of Saxe-Coburg and Gotha, before he became King George IV; that is, the period in United Kingdom history in which he ruled as prince regent (1811–1820).

plural of regency

(obsolete) rule