Ancient heretics, who made their appearance in the reign of the emperor Trajan, and took their name from their leader, Elcesai. They kept a mean between the Jews, Christians, and Pagans: they worshipped but one God, observed the Jewish sabbath, circumcision, and the other ceremonies of the law; yet they rejected the Pentateuch and the prophets: nor had they any more respect for the writings of the apostles.