Undersea Meaning

/ˌʌndəˈrsi/
B2

Definition, CEFR level B2, pronunciation, examples, and quiz.

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adjExisting, relating to, or made for use beneath the sea.

A tsunami is a series of waves caused by earthquakes or undersea volcanic eruptions.
The bathysphere is a new technology for undersea travel.
Synonyms:
Antonyms:
CEFR Practice Quiz
The team of divers investigated the ____ ruins of an ancient city that sank centuries ago.
CEFR Practice Quiz (Alternate)
The scientists used a small robotic submarine to explore the ____ mountain range and find any new species of life today.

Etymology tree Proto-Indo-European *h₁én Proto-Indo-European *h₁entér Proto-Indo-European *(H)n̥dʰí Proto-Indo-European *-ér Proto-Indo-European *(H)n̥dʰér Proto-Germanic *under Proto-West Germanic *undar Old English under- Middle English under- English under- English sea English undersea From under- + sea.

"It is not known just what action will be taken against the captain of the undersea boat." — 1920, George M. Battey, Jr., 70, 000 Miles on a Submarine Destroyer, Webb & Vary Company, page 133:
""You're right!" she cried. "I'm sure you are." Twenty reasons come back. An undersea tunnel to the little island." — 1923, The Saturday Evening Post, G. Graham, page 58:
"The Sediment (SNAP-7E) Density Meter (an underwater rocket) has been developed to investigate to an ocean-bottom depth of 11 sedimentary feet. Sea Lab I, the Navy’s new undersea laboratory, complete with observation porch and garage, should become safe to operate at the 200 foot level." — 1966, Robert B. Thomas, The Old Farmer's Almanc, Yankee Pub, page 44:
"The bull kelp forests off Northern California are sometimes spoken of as the redwoods of the sea. And like the redwoods, these forests are in danger. In less than a decade, these otherworldly undersea landscapes, lush with life, have all but disappeared along 200 miles of coast north of San Francisco's Golden Gate Bridge." — 2022 April 30, David Helvarg, “Climate change threatens another California forest, this one underwater”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 17 Aug 2025:
"The Channel Tunnel is the longest undersea tunnel in the world, with this section being 38km (23.6 miles) long." — 2022 December 28, “The essential Eurotunnel”, in RAIL, number 973, page 59:

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CEFR Practice Quiz
The team of divers investigated the ____ ruins of an ancient city that sank centuries ago.
CEFR Practice Quiz (Alternate)
The scientists used a small robotic submarine to explore the ____ mountain range and find any new species of life today.

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