adjective Etymology: French, from Hadès Hades Date: 1959 of, relating to, or being the parts of the ocean below 6000 meters (about 20,000 feet)
HADAL
Meaning of HADAL in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012