abyssal
adj.adj. relating to the very deep part of the ocean floor. It describes things that live in or are found in the dark, cold depths of the sea.
adj. relating to the deep ocean floor, specifically the region beyond the continental shelf. Often used in scientific contexts to describe geological or biological features of the deep sea.
The abyssal plain is covered in thick layers of mud.
Scientists use special submersibles to study the abyssal life forms that survive in total darkness.
The abyssal trenches represent some of the most extreme environments on Earth, where pressure is immense and sunlight cannot penetrate the surface for thousands of meters.
First attested in the 1690s. From Medieval Latin abyssalis, from Latin abyssus (“abyss”) + -alis (“-al”). Equivalent to abyss + -al.