Legate
Webster's Dictionary [1]
(1): ( n.) An official assistant given to a general or to the governor of a province.
(2): ( n.) An ecclesiastic representing the pope and invested with the authority of the Holy See.
(3): ( n.) An ambassador or envoy.
(4): ( n.) Under the emperors, a governor sent to a province.
Charles Buck Theological Dictionary [2]
A cardinal, or bishop whom the pope sends as his ambassador to sovereign princes.
The Nuttall Encyclopedia [3]
The title of the Pope's representative or ambassador; in medieval times this office was attached to certain bishoprics, and the bishops were styled legati nati; besides these there were legati a latere , generally cardinals, and legati missi , or nuncios specially appointed; legates used to claim full papal jurisdiction within their provinces, which caused many disputes; now they are ambassadors for spiritual purposes at Roman Catholic Courts—Vienna, Münich, Madrid, Lisbon, and Paris—and do not interfere with the authority of the bishops.
