in ecclesiastical antiquity, a sort of resident in an imperial city, in the name of a foreign church or bishop, whose office was to negotiate, as proctor at the emperor's court, in all ecclesiastical causes in which his principals might be concerned. The institution of the office seems to have been in the time of Constantine, or not long after, when, the emperors being become Christians, foreign churches had more occasions to promote their suits at court than formerly. However, we find it established by law in the time of Justinian. In imitation of this officer, almost every monastery had its Apocrisarius, or resident, in the imperial city.

The title and quality of Apocrisary became at length appropriated to the pope's agent, or *nuncio*, as he is now called; who resided at Constantinople, to receive the pope's despatches, and the emperor's answers. The word is formed from *ἀποκρίνω*, to answer.