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Showing results for undersea. Search instead for under-seam.
Synonyms

undersea

American  
[uhn-der-see] / ˈʌn dərˌsi /

adjective

  1. located, carried on, or used under the surface of the sea.

    undersea life.

adverb

  1. underseas.

undersea British  
/ ˈʌndəˌsiː /

adjective

  1. below the surface of the sea

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of undersea

First recorded in 1605–15; under- + sea

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Some of the crucial work done at Bell Labs might now seem mundane: for example, how to fabricate sheathing so undersea cables wouldn’t be chewed through by Toredo worms.

From The Wall Street Journal • Mar. 28, 2026

The search for mines can include divers, unmanned undersea vehicles and specialized ships.

From The Wall Street Journal • Mar. 12, 2026

"It didn't stand a chance. The incident confirms the sophistication of the means of American undersea warfare."

From Barron's • Mar. 6, 2026

US submarine forces commander Vice Admiral Richard Seif told an American congressional committee this week that China's "formidable" next-generation submarines "challenge the US Navy's longstanding undersea dominance".

From Barron's • Mar. 6, 2026

The grass swayed and rustled around her like the tentacles of a gigantic undersea anemone.

From "The Son of Neptune" by Rick Riordan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.