- n abyssal zone the deep sea (2000 meters or more) where there is no light
Webster's Revised Unabridged Dictionary
- Abyssal zone (Phys. Geog) one of the belts or zones into which Sir E. Forbes divides the bottom of the sea in describing its plants, animals, etc. It is the one furthest from the shore, embracing all beyond one hundred fathoms deep. Hence, abyssal animals, plants, etc.
- Abyssal zone (Phys. Geog) See under Abyssal.