undersea
/ˈʌndərˌsi/
adjective
- Located, occurring, or used beneath the surface of the sea.
- The undersea cable connects the two continents for internet traffic.
- The submarine explored an undersea canyon deeper than the Grand Canyon.
- Marine biologists study undersea volcanoes to understand ocean ecosystems.
Synonyms
adverb
- Beneath the surface of the sea.
- The research vessel sent a robot to operate undersea for several hours.
- The treasure lay undersea for centuries before being discovered.
- Many species of fish live undersea in coral reefs.