G3466–μυστήριον–mustērion

but in the days of the voice of the seventh angel, when he is about to sound, then the mystery of God is finished, as he declared to his servants, the prophets.

μυστήριον mustērion “mystery”

And on her forehead a name was written, "MYSTERY, BABYLON THE GREAT, THE MOTHER OF THE PROSTITUTES AND OF THE ABOMINATIONS OF THE EARTH."

μυστήριον, mustērion “a mystery:”

The angel said to me, "Why do you wonder? I will tell you the mystery of the woman, and of the beast that carries her, which has the seven heads and the ten horns.

μυστήριον mustērion “mystery”