estuary

American  

[es-choo-er-ee] / ˈɛs tʃuˌɛr i /

noun

• estuaries
  plural

1. that part of the mouth or lower course of a river in which the river's current meets the sea's tide.

2. an arm or inlet of the sea at the lower end of a river.

---

estuary British  

/ ˌɛstjʊˈɛərɪəl, ˈɛstjʊərɪ /

noun

1. the widening channel of a river where it nears the sea, with a mixing of fresh water and salt (tidal) water

2. an inlet of the sea

---

estuary Scientific  

/ ĕs′cho̅o̅-ĕr′ē /

1. The wide lower course of a river where it flows into the sea. Estuaries experience tidal flows and their water is a changing mixture of fresh and salt.

2. An arm of the sea that extends inland to meet the mouth of a river.

---

estuary Cultural  

1. A wide body of water formed where a large river meets the sea. It contains both fresh and salt water.

---

Other Word Forms

Derived Forms

• estuarial
  adjective

Inflected Forms

Nouns

• estuaries
  plural

Etymology

Origin of estuary

First recorded in 1530–40; from Latin aestuārium “channel, creek, inlet,” from aestu(s) “fire, heat, tide” + -ārium -ary

Explanation

An estuary is the place in the water where a tide and a river current meet, like the estuary at New York Harbor, where the Hudson River meets the Atlantic Ocean. Estuary, pronounced "ES-choo-air-ee," comes from the Latin word aestuarium, meaning "a tidal marsh or opening." The calm waters of an estuary, where the mouth of a river connects with the open sea and fresh water mixes with salty ocean water, makes the perfect home for many species of aquatic plants and animals. Chesapeake Bay and Puget Sound are estuaries.

Example Sentences

See Examples For:

estuary estuaries

According to Williams, Y Foryd area and the Afon Seiont estuary were "great places for him", as he feeds in a similar way to a Little egret, searching for and eating small fish.

From BBC ● Jun. 9, 2026

Much of the uncaptured Mexican waste flows into the Tijuana River, which crosses a U.S. estuary before reaching the Pacific.

From The Wall Street Journal ● May 4, 2026

The 4,140-sq-km bay is the largest estuary on the west coast of the US.

From BBC ● Apr. 19, 2026

The tidal Scheldt river estuary is the main maritime access route to Antwerp port, along with several narrower canals primarily used for inland navigation.

From Barron's ● Apr. 10, 2026

There to the left of us was the silver streak of the river, widening to the estuary at Kerrith six miles away.

From "Rebecca" by Daphne du Maurier

Sewage discharges, runoff of fertilisers and manures from farms and wastewater from industry can all increase nutrient levels in rivers and estuaries.

From BBC ● May 2, 2026

They placed groups of these tiles in three estuaries in the Sydney region, Brisbane Water, the Hawkesbury River and Port Hacking, near existing oyster reefs where larvae are present.

From Science Daily ● Apr. 6, 2026

They are also found around river mouths, estuaries and manmade structures like piers and groynes.

From BBC ● Aug. 23, 2025

Currently, more than 8,000 people live in flood plain areas along estuaries in the Cascadia coastal region.

From Los Angeles Times ● Apr. 30, 2025

Instead people spread themselves through estuaries, sometimes grouping into neighborhoods, sometimes with each family on its own, its maize ground proudly separate.

From "1491" by Charles C. Mann

Related Words

• inlet
• waterway