hadal

[ heyd-l ]

adjective

, Oceanography.

1. of or relating to the greatest ocean depths, below approximately 20,000 feet (6,500 meters).
2. of or relating to the biogeographic region of the ocean bottom below the abyssal zone.

hadal

/ ˈheɪdəl /

adjective

1. See abyssal
   of, relating to, or constituting the zones of the oceans deeper than abyssal: below about 6000 metres (18 000 ft) See also abyssal

hadal

/ hād′l /

1. Relating to the deepest regions of the ocean, below about 6,000 m (19,680 ft). The hadal zone mostly comprises trenches that can reach depths greater than 10,000 m (32,800 ft).

Word History and Origins

Origin of hadal¹

First recorded in 1955–60; Had(es) + -al ¹

Word History and Origins

Origin of hadal¹

C20: from French, from Hadés Hades

Example Sentences

They can operate autonomously, which they’ll do at the hadal depths, but can also work while connected to a tether.

From Popular-Science