'Bottomless Pit' in the Bible

And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.

And he opened the bottomless pit; and there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.

And they had a king over them, who is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue he has the name Apollyon.

And when they shall have finished their testimony, the beast that ascends out of the bottomless pit shall make war against them, and shall overcome them, and kill them.

The beast that you saw was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is.

And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand.

And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled: and after that he must be loosed a little while.