(1.) A term used in reference to the consecrated bread of the Eucharist. In the early Church, at the end of mass, the loaves offered by the faithful (not consecrated) were blessed by the celebrant, and distributed as a sign of communion, as they now are in the Greek Church, to those who had not communed, and formerly to catechumens who were not admissible. They were called eulogies or antidora, compensations, by the Council of Antioch in 341.
(2.) Εὐλογία was one of the early titles of the sacrament of the Lord's Supper, and appears to have been taken from the language of Paul when he says, "The cup of blessing which we bless" — τὸ ποτήριον τῆς εὐλογίας. Down to the time of Cyril and Chrysostom, εὐλογία is used synonymously with εὐχαριστία, but after the fifth century the term was appropriated to the bread set apart from the oblations for the poor and the clergy. To this custom we may refer the origin of private masses, and of communion in one kind.
(3.) The practice of giving the eulogia also tends to explain the custom of non-communication which sprang up in the Church about the same time. The faithful who did not communicate retired from the assembly before the celebration of the Lord's Supper began, but not without receiving the benediction of the minister. The fideles were soon divided into two classes — communicantes and non-communicantes — of which the Church knew nothing in earlier ages. The Council of Nantes, about A.D. 890, ordered the presbyters to keep some portions of the oblations in a proper vessel, so that those persons who were not prepared to communicate might, on every festival and Lord's day, receive some of the euloqia, previously blessed with a proper benediction. — Bingham, Orig. Eccl. book 10, chapter 2, § 16; book 15, chapter 4, § 3; Riddle, Christ. Antiquities, pages 545, 578.