es·​tu·​ary | \ ˈes-chə-ˌwer-ē How to pronounce estuary (audio) , ˈesh- \
plural estuaries

Definition of estuary

: a water passage where the tide meets a river current especially : an arm of the sea at the lower end of a river

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Synonyms for estuary


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A partly enclosed coastal body of water in which river water is mixed with seawater is called an estuary. An estuary is thus defined by salinity rather than geography. Many coastal features designated by other names are in fact estuaries (for instance, Chesapeake Bay). Some of the oldest continuous civilizations have flourished in estuarine environments (for example, the Tigris and Euphrates rivers, the Nile delta, and the Ganges delta). Cities such as London (Thames River), New York (Hudson River), and Montreal (St. Lawrence River) developed on estuaries and became important commercial centers.

Examples of estuary in a Sentence

the city sits on the shores of a deep estuary where the Hudson River meets the Atlantic Ocean
Recent Examples on the Web That said, the British government is making poor planning decisions regarding sea-level rise and is kicking the can on carbon emissions, so my story about rising seas in the Thames estuary is largely a cautionary tale. Bill Mckibben, The New Yorker, 12 May 2021 The football and men’s basketball seasons were long over, but other sports at the University of California, Berkeley, were in full array — water polo in the pool, rowing in the estuary, baseball on the diamond. New York Times, 10 May 2021 In the Indian River Lagoon alone, two phytoplankton blooms devastated seagrass in 2011, followed by two years of brown algae blooms, ultimately killing 47,000 acres of seagrass, or about 60% overall in the estuary. Jim Waymer, USA TODAY, 8 May 2021 The lake isn’t the only water feature, either: There are waterfalls at Houghton Falls State Natural Area; two rivers, the Onion and Sioux; and a coastal estuary at Frog Bay Tribal National Park, the country’s first tribal national park. Washington Post, 16 Apr. 2021 Last week Biden directed federal agencies to review a list of policies that includes pumping operations in the Sacramento-San Joaquin River Delta, the hub of California’s water supply and an estuary that’s struggling with too little water. Kurtis Alexander,, 24 Jan. 2021 Where a bottom was found, in a large northern estuary, some signals bounced back from the surface while others penetrated the liquid and echoed off the seafloor, says planetary scientist Valerio Poggiali of Cornell University. Sid Perkins, Scientific American, 23 Apr. 2021 Deméré said the fossilized shells included oysters, clams, snails and barnacles from the Pliocene and Pleistocene epochs, a time when the East Village area was an estuary. San Diego Union-Tribune, 24 Apr. 2021 On days when the estuary is open to retention fishing, all sturgeon angling will be closed after 2 p.m. That includes catch-and-release. oregonlive, 23 Mar. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'estuary.' 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 estuary

1538, in the meaning defined above

History and Etymology for estuary

Latin aestuarium, from aestus boiling, tide; akin to Latin aestas summer — more at edify

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Time Traveler for estuary

Time Traveler

The first known use of estuary was in 1538

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Statistics for estuary

Last Updated

6 Jun 2021

Cite this Entry

“Estuary.” Dictionary, Merriam-Webster, Accessed 15 Jun. 2021.

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More Definitions for estuary



English Language Learners Definition of estuary

: an area where a river flows into the sea


es·​tu·​ary | \ ˈes-chə-ˌwer-ē How to pronounce estuary (audio) \
plural estuaries

Kids Definition of estuary

: an arm of the sea at the lower end of a river

More from Merriam-Webster on estuary

Thesaurus: All synonyms and antonyms for estuary

Nglish: Translation of estuary for Spanish Speakers Encyclopedia article about estuary


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