katechon

“+ The Apostle refers immediately to contemporary men and events, which are, however, types of the eschatological katechon, "man of sin", and day of the Lord; the destruction of Jerusalem, e.g., is the type of the Lord's second coming, etc.”

The Catholic Encyclopedia, Volume 1: Aachen-Assize

“But he adds a clause calculated to determine the time of the main event more accurately; he describes something first as a thing (to datechon), then as a person (ho katechon), preventing the occurrence of the main event: "Only he who now holdeth, do hold, until he be taken out of the way.”

The Catholic Encyclopedia, Volume 1: Aachen-Assize

“For by to katechon (ho katechōn), “that which (or he who) restrains,” we must understand the Roman empire.”

The Mission and Expansion of Christianity in the First Three Centuries

“Irenaeus, who died 189, remarks: Every Christian "who retains immovable in himself the rule of the truth which he received through Baptism (_ho ton kanona tes altheias akline en eauto katechon, hon dia tou baptismatos eilephe_)" is able to see through the deceit of all heresies.”

Historical Introductions to the Symbolical Books of the Evangelical Lutheran Church

“man of sin" (most Latin Fathers and later interpreters) + The Apostle referred to persons and events of his own time; the katechon and the "man of sin" are variously identified with the”

The Catholic Encyclopedia, Volume 1: Aachen-Assize