un·der·sea
ˌən-dər-ˈsē 
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
Examples of undersea in a Sentence
Adjective
They are conducting undersea research.
Recent Examples on the Web
Amanda Castro, MSNBC Newsweek, 4 Dec. 2025
The project aims to create a record-breaking undersea route beneath Norway’s rugged coastline, ultimately providing a direct, ferry-free connection between Stavanger and Bergen.
—Georgina Jedikovska, Interesting Engineering, 3 Dec. 2025
Several undersea data cables and a key power link were damaged that November and December, including on Dec. 25.
—Efrat Lachter, FOXNews.com, 1 Dec. 2025
While specs haven’t been released, for security reasons, the Ghost Shark looks to be the size of a large shipping container and its modular construction will allow it to be customized for a range of undersea missions.
—Brad Lendon, CNN Money, 27 Nov. 2025
See All Example Sentences for undersea
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Adjective
Russia has been accused of cutting vital undersea communications cables in the Baltic Sea, part of its hybrid warfare against European NATO allies.
—Amanda Castro, MSNBC Newsweek, 4 Dec. 2025
The project aims to create a record-breaking undersea route beneath Norway’s rugged coastline, ultimately providing a direct, ferry-free connection between Stavanger and Bergen.
—Georgina Jedikovska, Interesting Engineering, 3 Dec. 2025
Several undersea data cables and a key power link were damaged that November and December, including on Dec. 25.
—Efrat Lachter, FOXNews.com, 1 Dec. 2025
While specs haven’t been released, for security reasons, the Ghost Shark looks to be the size of a large shipping container and its modular construction will allow it to be customized for a range of undersea missions.
—Brad Lendon, CNN Money, 27 Nov. 2025
See All Example Sentences for undersea
Cite this Entry
“Undersea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undersea. Accessed 8 Dec. 2025.
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