Reference: DEEP AND DEPTHS
American
The deep, or the great deep, signifies in Scripture, hell, the place of punishment, the bottomless pit, Lu 8:31, compare Re 9:1; 11:7; the grave, Ro 10:7; the deepest parts of the sea, Ps 69:15; 107:26; chaos in the beginning of the world, Ge 1:2. See HELL.
See Verses Found in Dictionary
Now the earth was formless and empty. Darkness was on the surface of the deep. God's Spirit was hovering over the surface of the waters.
Don't let the flood waters overwhelm me, neither let the deep swallow me up. Don't let the pit shut its mouth on me.
They mount up to the sky; they go down again to the depths. Their soul melts away because of trouble.
They begged him that he would not command them to go into the abyss.
or, 'Who will descend into the abyss?' (that is, to bring Christ up from the dead.)"
The fifth angel sounded, and I saw a star from the sky which had fallen to the earth. The key to the pit of the abyss was given to him.
When they have finished their testimony, the beast that comes up out of the abyss will make war with them, and overcome them, and kill them.