What is the meaning of Ancien_régime?

A system of government long since supplanted by another, particularly a state of feudalism with an absolute monarchy supported by the doctrine of divine right with the explicit consent of an established church.

‖ancien régime” listed in the Oxford English Dictionary [2 Ed.; 1989]

former government

former government

ancien régime (system of government long since supplanted by another)

Source: wiktionary.org