Originally, the chief notary; and anciently, the title of the principal notaries of the emperors of Constantinople. Hence,

In England, an officer in the court of king’s bench and common pleas. The prothonotary of the king’s bench records all civil actions. In the common pleas, the prothonotaries, of which there are three, enter and enroll all declarations, pleadings, judgments, make out judicial writs and exemplifications of records, enter recognizances.

In the United States, a register or clerk of a court. The word however is not applied to any officer, except in particular states. Apostolical prothonotaries, in the court of Rome, are twelve persons constituting a college, who receive the last wills of cardinals, make informations and proceedings necessary for the canonization of saints.