Mid 17th century; earliest use found in John Davies (1625–1693), translator. After post-classical Latin protodiaconus or its etymon Byzantine Greek πρωτοδιάκονος; compare French protodiacre.
Definition of proto-deacon in US English:
proto-deacon
noun
Orthodox Church
A senior deacon.
Origin
Mid 17th century; earliest use found in John Davies (1625–1693), translator. After post-classical Latin protodiaconus or its etymon Byzantine Greek πρωτοδιάκονος; compare French protodiacre.