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
Prabhat Ranjan Mishra, Interesting Engineering, 22 Apr. 2026
The ship’s vertical structure will be a magnet for fish and undersea creatures.
—Erin Gifford, Southern Living, 19 Apr. 2026
This is the latest of multiple dual-use technologies for cutting undersea cables developed by Chinese military and civilian organizations over the years.
—Jonathan M. Gitlin, ArsTechnica, 16 Apr. 2026
Add cybersecurity and undersea cables to the brief, and the stakes become clear.
—Margrethe Vestager, Time, 15 Apr. 2026
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Adjective
As undersea threats continue to evolve, the need for advanced, adaptive defense systems becomes increasingly urgent.
—Prabhat Ranjan Mishra, Interesting Engineering, 22 Apr. 2026
The ship’s vertical structure will be a magnet for fish and undersea creatures.
—Erin Gifford, Southern Living, 19 Apr. 2026
This is the latest of multiple dual-use technologies for cutting undersea cables developed by Chinese military and civilian organizations over the years.
—Jonathan M. Gitlin, ArsTechnica, 16 Apr. 2026
Add cybersecurity and undersea cables to the brief, and the stakes become clear.
—Margrethe Vestager, Time, 15 Apr. 2026
See All Example Sentences for undersea
Cite this Entry
“Undersea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undersea. Accessed 23 Apr. 2026.
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