Intercessor
Intercessor , noun
[Latin, a surety: compare French intercesseur.]
1.
One who goes between, or intercedes; a mediator.
(a)
One who interposes between parties at variance, with a view to reconcile them.
(b)
One who pleads in behalf of another. — Milton
2.
(Ecclesiastical) A bishop, who, during a vacancy of the see, administers the bishopric till a successor is installed.