Strong G5421 φρέαρ phrear · well/abyss

Revelation

1. Revelation 9:1
   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.
2. Revelation 9:2
   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.