Brewer's: Fathers of the Church
The early advocates of Christianity, who may be thus classified:—(1) Five apostolic fathers, who were contemporary with the apostles—viz. Clement of Rome, Barnabas, Hermas, Ignatius, and Polycarp.
(2) The primitive fathers. Those advocates of Christianity who lived in the first three centuries. They consisted of the five apostolic fathers (q.v.), together with the nine following:— Justin, Theophilus of Antioch, Irenæ'us, Clement of Alexandria, Cyprian of Carthage, Origen, Gregory Thaumaturgus, Dionysius of Alexandria, and Tertullian.
(3) The fathers, or those of the fourth and fifth century, who were of two groups, those of the Greek and those of the Latin Church. (See below.)