"Antipas is the proper name of a man; so a son of Herod was called, even he that beheaded John, and mocked Christ: and there might be a man of this name at Pergamos, that might suffer martyrdom for the Gospel of Christ; and who was an emblem of the confessors, witnesses, and martyrs, that suffered for Christ, in this period of time, through their opposition to the popes of Rome; for Antipas is the contraction of Antipater, and is the same with Antipapas, or Antipappas, which signifies one that is against the pope, an opposer of that holy father; and so intends all those that made head against him, upon his rising and revelation, and when he assumed the power he did to himself; such as the Waldenses and Albigenses particularly, who set themselves against him, openly declared that the pope was antichrist, and that his government was tyrannical, and his doctrines the doctrines of devils, abominable and fabulous. They bore a faithful testimony against all his corruptions and innovations, and became martyrs in the cause of Christ, many thousands of them being slain for his sake within the dominions of this firstborn of Satan. The Alexandrian copy reads 'Anteipas'; and his name is left out in the Syriac and Arabic versions."
(The New John Gill's Exposition of the Entire Bible)
"A martyr of the church of Pergamum, mentioned only in Revelation 2:13, unless some credit is to be given to the late accounts of his martyrdom. According to these, he was roasted to death in a brazen bowl in the days of Domitian."
(Hastings' Dictionary of the Bible)