es·​tu·​ary | \ ˈes-chə-ˌwer-ē, 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

Her husband installed a telescope in the clock tower and enjoyed sailing in the Tagus River estuary just beyond the property. J. S. Marcus, WSJ, "When Home Is a Portuguese Bachelor Pad Fit for a King," 25 July 2018 LiveScience reports that the blanket of goo is choking the estuary near Florida’s southeastern coast. James Rogers, Fox News, "Blue-green toxic algae invades Florida river," 15 Aug. 2018 Citing the Florida Department of Environmental Protection, TCPalm reports that a recent sample taken from the St. Lucie River estuary contained toxins that are 10 times the level considered hazardous. James Rogers, Fox News, "Blue-green toxic algae invades Florida river," 15 Aug. 2018 This is the project in a clamshell: Two 35-mile, 40-foot-wide tunnels under the delta from the estuary’s northern end on the Sacramento River to aqueducts at the southern edge. George Skelton,, "What do Southern Californians really get out of Gov. Jerry Brown's twin tunnels project?," 12 July 2018 Image The house that Bruce Beinfield built on a thin spit of land overlooking a picturesque tidal estuary in Connecticut comes with a whimsical barn-themed facade and a contentious back story. Lisa Prevost, New York Times, "In Rowayton, a Narrow House That Feels Wide Inside," 22 June 2018 Just to the west of the beach is Malibu Lagoon, a state park with ample birding, and a path around the estuary lined with California native plants. Maxwell Williams, Condé Nast Traveler, "13 Best Beaches in Los Angeles," 28 Feb. 2018 Walleyes for Tomorrow assisted the estuary plan by providing $25,000 to the DNR to raise walleyes at the Lake Mills hatchery and stock them in the Milwaukee harbor. Paul A. Smith, Milwaukee Journal Sentinel, "Walleyes For Tomorrow organization makes push to restore fishery in Milwaukee River," 3 Mar. 2018 Environmentalists, Delta farmers and Sacramento Valley government officials say the WaterFix project would bring even more harm to the fragile estuary whose northern reaches start just a few miles south of Sacramento. Ryan Sabalow, sacbee, "Did Gov. Brown promise the Bay Area a new reservoir in exchange for Delta tunnels support? | The Sacramento Bee," 30 Apr. 2018

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

3 Jan 2019

Look-up Popularity

Time Traveler for estuary

The first known use of estuary was in 1538

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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 \
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

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a complex dispute or argument

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