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

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 In 2000, floods caused by Tropical Cyclone Eline destroyed half of the mangroves in the estuary where the Limpopo River opens to the Indian Ocean. Erika Page, The Christian Science Monitor, 21 June 2022 The juvenile, some 30 feet long, was found near the inlet of a large estuary that might have been used as a breeding and calving grounds similar to those favored by living gray whales in the shallow bays and lagoons off Baja California. Brian Handwerk, Smithsonian Magazine, 19 July 2022 Each of the guest rooms, most with large balconies, offers unobstructed views of the Sound, a tidal estuary of the Atlantic Ocean. Irene S. Levine, Forbes, 4 July 2022 For years, environmental regulators thought sewage pouring over the border from Mexico was largely the result of heavy winter rains that flushed polluted runoff and wastewater through the Tijuana River channel into the estuary in Imperial Beach. Joshua Emerson Smith, San Diego Union-Tribune, 14 June 2022 Along Florida’s Atlantic coast, the die-off began last year, after the Indian River Lagoon, a 156-mile estuary that had been a seasonal manatee refuge, turned into a barren underwater desert. New York Times, 9 Apr. 2022 Add two days to sturgeon retention fishing in the estuary. Bill Monroe, oregonlive, 2 June 2022 The San Francisco Bay Delta is the largest estuary on the West Coast. Ian James, Los Angeles Times, 1 Apr. 2022 Poachers, following a similar logic, have long raided the great estuary of Jamaica Bay, at the southeastern edge of Brooklyn and Queens—in the metro area, it’s where the wildlife is. Erik Baard, The New Yorker, 6 Apr. 2022 See More

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.

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

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The first known use of estuary was in 1538

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Dictionary Entries Near estuary

estuarine crocodile



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Last Updated

5 Aug 2022

Cite this Entry

“Estuary.” Dictionary, Merriam-Webster, Accessed 11 Aug. 2022.

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More Definitions for estuary


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

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


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