undersea

1 of 2

adjective

un·​der·​sea ˌən-dər-ˈsē How to pronounce undersea (audio)
1
: being or carried on under the sea or under the surface of the sea
undersea oil deposits
undersea fighting
2
: designed for use under the surface of the sea
an undersea fleet

undersea

2 of 2

adverb

variants or underseas
: under the sea : beneath the surface of the sea
photographs taken undersea

Examples of undersea in a Sentence

Adjective They are conducting undersea research.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
The cable, connecting Taiwan's main island to a Taiwanese outlying island that is also close to China, is the third Taiwanese undersea cable in two years to be severed under suspicious circumstances. Emily Feng, NPR, 27 Feb. 2025 Taiwan and China have also traded barbs this week over the severing of an undersea communications cable off the island’s southwest coast. Reuters, NBC News, 26 Feb. 2025 Washington’s best option is to transport military supplies using uncrewed systems, including aircraft, surface vessels, and undersea vehicles, because even if the PLA fired on them, the United States would suffer no casualties and could avoid entering into a war. Jennifer Kavanagh, Foreign Affairs, 25 Feb. 2025 Taiwan usually depends on undersea cables for its internet connections with outlying islands, such as the Penghu Islands, as well as for its connections to the rest of the world. Chris Buckley, New York Times, 25 Feb. 2025 See All Example Sentences for undersea

Word History

First Known Use

Adjective

1613, in the meaning defined at sense 1

Adverb

1645, in the meaning defined above

Time Traveler
The first known use of undersea was in 1613

Cite this Entry

“Undersea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undersea. Accessed 9 Mar. 2025.

Kids Definition

undersea

adjective
un·​der·​sea
ˈən-dər-ˈsē
1
: being or carried on under the sea or under the surface of the sea
undersea oil deposits
undersea warfare
2
: designed for use under the surface of the sea
undersea fleet

More from Merriam-Webster on undersea

Last Updated: - Updated example sentences
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