Provisional bishop

A provisional bishop in the Episcopal Church (United States) is a bishop — either retired or concurrently holding another episcopal post (such as in a neighbouring diocese) — who serves as the bishop of a particular diocese during a vacancy in that See. The provisional bishop may then serve either for an agreed period of time or until a new diocesan bishop is elected and consecrated — but both at the pleasure of the diocese's Convention. Provisional bishops are appointed under Canon III.13 of the Constitution and Canons of the Episcopal Church, 2012.

...
Wikipedia