Notes on The First Epistle of St. John the Apostle (Author Bishop Richard Challoner (ed.))
2:18 It is the last hour: That is, it is the last age of the world. Many Antichrists;. . .that is, many heretics, enemies of Christ and his church, and forerunners of the great Antichrist.
Original Douay-Rheims from Project Gutenberg - Massive cleanup of OCR problems and editing done locally.