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


arm, bay, bight, cove, creek [chiefly British], embayment, firth, fjord (also fiord), gulf, inlet, loch [Scottish]

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Did You Know?

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

Our Bay Area estuary is a confluence where fresh water from rivers and streams meet and mix with salt water from the ocean. Marcela Davison Aviles, The Mercury News, "Opinion: Oil drilling in the Bay Area? Trump administration can’t be serious," 5 Sep. 2019 The spill has polluted more than 200 square miles of water, damaging mangrove forests and estuaries. Muktita Suhartono, New York Times, "Indonesia Confronts, Belatedly, a Huge Oil Spill Near Jakarta," 27 Aug. 2019 The footpath is marked on the maps by a confident straight line just north of the mouth of the mighty River Thames and its estuary, running for six miles through a vast delta called the Maplin Sands. William Booth, Washington Post, "Britain’s deadliest path," 26 July 2019 So the professor was taken aback when Mr. Johnson publicly named him chairman of a team investigating a Thames estuary airport. Benjamin Mueller, New York Times, "Sure, Boris Johnson Is Funny. But Has He Ever Done a Job Well?," 22 July 2019 Visitors can pick out sights like the Pearl Harbor Memorial Bridge, the scenic Quinnipiac River flowing through its marsh estuary and even a distant Long Island across a swath of blue Long Island Sound. Peter Marteka,, "The ruins of the Hermitage and the spectacular views from Peter’s Rock in North Haven," 19 July 2019 Officials say clinging jellyfish typically attach themselves to underwater aquatic vegetation and algae and have been found in other ponds and estuaries. USA TODAY, "‘Molly of Denali,’ saloon discourse, ashes by mail: News from around our 50 states," 10 July 2019 Following this meager schooling, García continued to fish the rivers and estuaries and the open waters of the Pacific Ocean, to help support his family. Charles David Kleymeyer, Smithsonian, "Meet Juan García Salazar, the Man Who Championed Black Identity in Ecuador," 14 June 2019 The torrent of river water pushing into Gulf estuaries is decimating crab, oyster, and shrimp populations. Rocky Kistner, WIRED, "Gulf Fisheries Are Under Siege—Now Comes Tropical Storm Barry," 12 July 2019

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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Statistics for estuary

Last Updated

12 Sep 2019

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Time Traveler for estuary

The first known use of estuary was in 1538

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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

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More from Merriam-Webster on estuary

Rhyming Dictionary: Words that rhyme with estuary

Thesaurus: All synonyms and antonyms for estuary

Spanish Central: Translation of estuary

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

Comments on estuary

What made you want to look up estuary? Please tell us where you read or heard it (including the quote, if possible).


one from the Upper Peninsula of Michigan

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