hadal: Meaning and Definition of
ha•dal
Pronunciation: (hād'l), [key]
— adj.
- of or pertaining to the greatest ocean depths, below approximately 20,000 ft. (6500 m).
- of or pertaining to the biogeographic region of the ocean bottom below the abyssal zone.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.