Underwater | Definition of Underwater by Merriam-Webster


un·​der·​wa·​ter | \ ˌən-dər-ˈwȯ-tər How to pronounce underwater (audio) , -ˈwä- \

Definition of underwater

1 : lying, growing, worn, performed, or operating below the surface of the water underwater plants
2 : being below the waterline of a ship
3a : having, relating to, or being a mortgage loan for which more is owed than the property securing the loan is worth
b : having, relating to, or being a stock option for which the price of the option is higher than the current market value of the stock

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Other Words from underwater

underwater adverb

Synonyms for underwater


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Examples of underwater in a Sentence

underwater plants don't require as much light to grow as surface plants a vessel designed for underwater exploration
Recent Examples on the Web Everything was muffled, as if that ear was underwater. New York Times, "She Suffered Balance Issues for Years. Was It a Brain Tumor?," 31 Mar. 2021 As many as half a million barrels could still be underwater today, according to old records and a recent UC Santa Barbara study that provided the first real glimpse of this pollution bubbling 3,000 feet under the sea. Los Angeles Times, "Deep-sea ‘Roombas’ will comb ocean floor for DDT waste barrels near Catalina," 10 Mar. 2021 While Biden earns high marks for his coronavirus response, his immigration policies are underwater, according to a new CNN-SSRS poll conducted between March 3-8. Katherine Doyle, Washington Examiner, "Biden immigration response taking on water amid influx at southern border," 10 Mar. 2021 Entering with a 17-18 record, this was about spending the weeklong All-Star break at .500, instead of, like most of this season, underwater. Ira Winderman, sun-sentinel.com, "Jimmy Butler returns to fuel Heat past Pelicans 103-93 in absence of Bam Adebayo," 5 Mar. 2021 After all, other submarines may be listening for unusual underwater noise. Kelsey D. Atherton, Popular Science, "The Royal Navy’s robotic sub will be a test bench under the sea," 26 Feb. 2021 There is no silver bullet to address underwater noise across all vessel types, says Transport Canada’s Sanders. Joseph Polidoro, Scientific American, "A Few Fixes Could Cut Noise Pollution That Hurts Ocean Animals," 23 Feb. 2021 Scientists worry that an iceberg could grind into the seabed of the wildlife-rich island of South Georgia and disrupt underwater ecosystems. NBC News, "Giant iceberg heading toward South Atlantic island breaks up," 23 Dec. 2020 Yet there’s a glimmer amid the gloom: the designation of Greece’s first underwater museum. Travel, "Diving into Greece’s first underwater museum," 2 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'underwater.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of underwater

1627, in the meaning defined at sense 1

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Time Traveler for underwater

Time Traveler

The first known use of underwater was in 1627

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Statistics for underwater

Last Updated

4 Apr 2021

Cite this Entry

Underwater.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underwater. Accessed 12 Apr. 2021.

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More Definitions for underwater



English Language Learners Definition of underwater

: located, used, done, or happening below the surface of water


un·​der·​wa·​ter | \ ˈən-dər-ˈwȯ-tər How to pronounce underwater (audio) , -ˈwä- \

Kids Definition of underwater

 (Entry 1 of 2)

: lying, growing, worn, performed, or operating below the surface of the water an underwater cave underwater somersaults


un·​der·​wa·​ter | \ ˌən-dər-ˈwȯ-tər How to pronounce underwater (audio) , -ˈwä- \

Kids Definition of underwater (Entry 2 of 2)

: under the surface of the water I like to swim underwater.



Legal Definition of underwater

1 : owing more on a mortgage loan than the property securing the loan is worth underwater homeowners
2 : being or relating to a mortgage loan in which more is owed than the property securing the loan is worth underwater mortgages underwater properties

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Comments on underwater

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