(1) A cleric, priest or bishop, who for grave and special reasons is appointed by the Holy See, to administer the diocese for an indefinite or for a specified time, which might be either till this particular see is vacant or, if vacant, until another bishop is appointed. The administrator has the same episcopal jurisdiction as the former bishop, and in exercising it he is bound by the same laws.

(2) Head priest of a cathedral in England: a priest who is appointed by the bishop to administer the affairs of a cathedral for the same reasons as those given above for a diocese.

(3) In the United States, a priest appointed to administer the affairs of a parish when an irremovable pastor makes an appeal to Rome against his removal from his benefice by the bishop; this administrator holds the office until a decision is given by the higher superiors. In Europe, a priest appointed by the superior of a convent to attend to the affairs of parishes which are under his jurisdiction.

(4) The administrator of ecclesiastical institutions, as seminaries, colleges, hospitals, asylums, convents, is usually a priest who attends to both the spiritual and material affairs of these institutions. Laymen are frequently appointed administrators of Church property and ecelesiastical institutions, but usually they are co-workers of the clergy.