Supernumerary judge

A supernumerary judge or supernumerary magistrates is a judge who has retired from their full-time position on a court, but continues to work on a part-time basis. Generally, when a judge becomes supernumerary a vacancy is created, and the appropriate person or body may subsequently make a new appointment to that Court.

The role of supernumerary judges varies by jurisdiction. In the United States federal courts, this describes the status of judges who have taken senior status. Supernumerary judges are widely used in Alabama, for example, where the chief justice of the state supreme court can assign retired judges or justices to act as supernumerary judges on any court of the state. Supernumerary judicial positions are also widely used in Canada.

...
Wikipedia