abyss
Hell; the bottomless pit; primeval chaos; a confined subterranean ocean.
'You cannot enter here,' said Gandalf, and the huge shadow halted. 'Go back to the abyss prepared for you! Go back! Fall into the nothingness that awaits you and your Master. Go!'
(frequently figurative) A bottomless or unfathomed depth, gulf, or chasm; hence, any deep, immeasurable; any void space.
Anything infinite, immeasurable, or profound.
Moral depravity; vast intellectual or moral depth.
An impending catastrophic happening.
(heraldry) The center of an escutcheon.
(oceanography) The abyssal zone.
(figurative) A difference, especially a large difference, between groups.