estuary

noun

es·​tu·​ary ˈes-chə-ˌwer-ē 

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.

Synonyms

• arm
• bay
• bight
• cove
• creek [chiefly British]
• embayment
• firth
• fjord
• fiord
• gulf
• inlet
• loch [Scottish]

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 list includes the Environmental Protection Agency’s Chesapeake Bay Program, which coordinates the multi-state cleanup effort for the nation’s largest estuary. —Christine Condon, Baltimore Sun, 26 Dec. 2024

Paddle and explore the diversity of this amazing estuary. —Joe Rassel, Orlando Sentinel, 4 Dec. 2024

While mugger crocodiles typically inhabit freshwater habitats such as lakes and rivers, saltwater crocodiles are known for their ability to travel between freshwater and marine environments, occasionally appearing along the coast, especially near estuaries or river mouths. —Thomas G. Moukawsher, Newsweek, 2 Dec. 2024

More than a century of land and water management has left our rivers, wetlands and estuaries in bad shape. —Letitia Grenier, The Mercury News, 26 Nov. 2024

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

Kids Definition

estuary

noun

es·​tu·​ary ˈes-chə-ˌwer-ē 

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