SYNCELLUS  , a hybrid word (Gr. vGv,

Lat. cella),' meaning literally " one who shares his cell with another." In ecclesiastical usage it refers to the very early custom of a priest or deacon living continually with a bishop, propter testimonium ecclesiasticum; thus Leo III. speaks of Augustine as having been the syncellus of Gregory the Great . The term came into use in the Eastern Church, where the syncelli were the chaplains of metropolitans and patriarchs . At Constantinople they formed a corporation, and the protosyncellus took precedence of metropolitans and ranked next to the patriarch, to whose office he generally succeeded .