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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

"Sea mines and other explosive devices can cause acoustic disturbance impacting sea mammals and other animals, and blast damage to natural undersea structures such as reefs," Weir said.

From Barron's • Mar. 17, 2026

Chile is hooked up to at least three international undersea cables, all connected to North America.

From Barron's • Mar. 12, 2026

Deep within the warship, behind a locked door in a windowless control room called the Combat Information Center, seasoned sub-hunters listen for sonar pings flagging an undersea target.

From The Wall Street Journal • Feb. 11, 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.