The abyssal zone is the abyssopelagic layer or pelagic zone that contains the very deep benthic communities near the bottom of oceans. "Abyss" derives from the Greek word ἄβυσσος, meaning bottomless. At depths of 4,000 to 6,000 meters (13,123 to 19,685 feet), this zone remains in perpetual darkness and never receives daylight. It is the deeper part of the midnight zone which starts in the bathyalpelagic waters above.
Its permanent inhabitants (for example, the black swallower, tripod fish, deep-sea anglerfish and the giant squid) are able to withstand the immense pressures of the ocean depths.
Abyss refers to a bottomless pit, to the underworld, to the deepest ocean floor, or to hell.
The English word "abyss" derives from the late Latin abyssimus (superlative of abyssus) through French abisme (abîme in modern French), hence the poetic form "abysm", with examples dating to 1616 and earlier to rhyme with "time".