Relating to the zone of the sea greater than 6000 m in depth (chiefly oceanic trenches).
超深渊的，离海面6, 000米以上水深的（主要指海沟）
Example sentencesExamples
The hadal environment (water depths greater than 6000m) is one of the last habitats on earth to be impacted by unsustainable human activity.
Submarine trenches usually develop downward from depths around 6,000 m, the beginning of the hadal region, exclusive domain of highly specialized and exquisite molluscan communities.
The hadal zone makes up only 1 or 2 percent of the ocean and is located in narrow oceanic trenches.
Origin
1950s: from Hades + -al.
Definition of hadal in US English:
hadal
adjectiveˈhādl
Relating to the zone of the sea greater than approximately 20,000 feet (6,000 m) in depth (chiefly oceanic trenches).
超深渊的，离海面6, 000米以上水深的（主要指海沟）
Example sentencesExamples
Submarine trenches usually develop downward from depths around 6,000 m, the beginning of the hadal region, exclusive domain of highly specialized and exquisite molluscan communities.
The hadal environment (water depths greater than 6000m) is one of the last habitats on earth to be impacted by unsustainable human activity.
The hadal zone makes up only 1 or 2 percent of the ocean and is located in narrow oceanic trenches.