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
Ivana Kottasová, CNN Money, 31 Dec. 2025
Finnish police on Wednesday seized a ship sailing from Russia on suspicion of sabotaging an undersea telecoms cable running from Helsinki to Estonia across the Gulf of Finland, an area hit by a string of similar incidents in recent years.
—Reuters, NBC news, 31 Dec. 2025
Authorities are investigating damage to an undersea telecommunications cable in the Gulf of Finland early Wednesday that occurred between the capitals of Finland and Estonia.
—Los Angeles Times, 31 Dec. 2025
After the runaway success of Titanic, Cameron began making a number of undersea documentaries, which were released theatrically in Imax 3-D in shorter versions and then on home video at longer, feature-length run times.
—Bilge Ebiri, Vulture, 19 Dec. 2025
See All Example Sentences for undersea
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
Finland has detained a ship and its crew after a critical undersea telecommunication cable connecting the country to Estonia was damaged Wednesday, Finnish authorities said.
—Ivana Kottasová, CNN Money, 31 Dec. 2025
Finnish police on Wednesday seized a ship sailing from Russia on suspicion of sabotaging an undersea telecoms cable running from Helsinki to Estonia across the Gulf of Finland, an area hit by a string of similar incidents in recent years.
—Reuters, NBC news, 31 Dec. 2025
Authorities are investigating damage to an undersea telecommunications cable in the Gulf of Finland early Wednesday that occurred between the capitals of Finland and Estonia.
—Los Angeles Times, 31 Dec. 2025
After the runaway success of Titanic, Cameron began making a number of undersea documentaries, which were released theatrically in Imax 3-D in shorter versions and then on home video at longer, feature-length run times.
—Bilge Ebiri, Vulture, 19 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 6 Jan. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share