estuary

noun

es·​tu·​ary ˈes-chə-ˌwer-ē How to pronounce estuary (audio)
ˈesh-
plural estuaries
: a water passage where the tide meets a river current
especially : an arm of the sea at the lower end of a river

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Flash rip currents are unpredictable, brief and affected by surf conditions, whereas a permanent rip is anchored to river estuaries or structures. Marshall Shepherd, Forbes.com, 22 July 2025 Powerful tidal currents in bays, estuary entrances, narrow straits, and inlets from the sea turn underwater turbines that are connected to a generator to produce electricity. Abhimanyu Ghoshal, New Atlas, 2 July 2025 The damage can easily be seen in the Indian River Lagoon, which reaches from Volusia to Martin along Florida’s east coast and is heralded as the nation’s most diverse estuary. Orlando Sentinel Editorial Board, The Orlando Sentinel, 26 June 2025 Photo by Frank Kennedy MN/Shutterstock Instead of Acadia National Park in Maine... Visit Voyageurs National Park in Minnesota More than 40 percent of Minnesota’s Voyageurs National Park is covered in a network of lakes, rivers, and estuaries, and there are water activities aplenty. Maggie Fuller, AFAR Media, 23 Apr. 2025 See All Example Sentences for estuary

Word History

Etymology

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

First Known Use

1538, in the meaning defined above

Time Traveler
The first known use of estuary was in 1538

Browse Nearby Words

Cite this Entry

“Estuary.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/estuary. Accessed 30 Jul. 2025.

Kids Definition

estuary

noun
es·​tu·​ary ˈes-chə-ˌwer-ē How to pronounce estuary (audio)
plural estuaries
: a passage where the tide meets a river current
especially : an arm of the sea at the lower end of a river
estuarine
ˈes-chə-wə-ˌrīn
adjective

More from Merriam-Webster on estuary

Last Updated: - Updated example sentences
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