Deep-sea (adjective)

1. Located in the depths of the sea, beyond the reach of sunlight and typically at depths greater than 200 meters.
2. Relating to or occurring in the deep sea.

Origin:

Compound of deep and sea, describing something that is located in the deep sea.

Examples:

1. Deep-sea creatures have adapted to living in the dark, cold, and high-pressure environment.
2. Deep-sea fishing is a method of catching fish that live at depths of 200 meters or more.
3. Deep-sea exploration is the study of the deep ocean and its inhabitants.
4. Deep-sea mining is the extraction of valuable minerals and other materials from the deep ocean floor.
5. Deep-sea trenches are the deepest parts of the ocean floor, reaching depths of more than 11,000 meters.