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
Gabe Whisnant, MSNBC Newsweek, 10 Dec. 2025
If their system works, the squishy descendants of WALL-E and R2D2 can look forward to undersea adventures – or in their miniature versions á la Fantastic Voyage, adventures inside your own body.
—New Atlas, 10 Dec. 2025
Deep-seabed mining would also advance another Chinese security imperative by facilitating the mapping of the seabed and the laying of undersea cables that can be used in support of naval and submarine warfare.
—Elizabeth Economy, Foreign Affairs, 9 Dec. 2025
Piranesi was an essential inspiration for Preston’s otherworldly, undersea journey in A Theory of Dreaming.
—Lizz Schumer, PEOPLE, 7 Dec. 2025
See All Example Sentences for undersea
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Adjective
The steep offshore trench and complex plate interactions in the region also heighten the risk of tsunamis generated by undersea seismic activity.
—Gabe Whisnant, MSNBC Newsweek, 10 Dec. 2025
If their system works, the squishy descendants of WALL-E and R2D2 can look forward to undersea adventures – or in their miniature versions á la Fantastic Voyage, adventures inside your own body.
—New Atlas, 10 Dec. 2025
Deep-seabed mining would also advance another Chinese security imperative by facilitating the mapping of the seabed and the laying of undersea cables that can be used in support of naval and submarine warfare.
—Elizabeth Economy, Foreign Affairs, 9 Dec. 2025
Piranesi was an essential inspiration for Preston’s otherworldly, undersea journey in A Theory of Dreaming.
—Lizz Schumer, PEOPLE, 7 Dec. 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 17 Dec. 2025.
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