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  

/ 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

Then we paddled around the estuary on a pre-breakfast kayak tour.

From Los Angeles Times ● Aug. 13, 2026

In Foynes village across the estuary from the refinery, where a port handles its exports, local businessman John Cassels said the dilemma was clear.

From Barron's ● Jul. 24, 2026

Along river mouths, this distance is extended to 500 metres with respect to the estuary.

From Science Daily ● May 21, 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 wind blew freshly into the estuary, a nervous, restless wind with the smell of storm on its breath, and there was change and uneasiness in the air.

From "The Pearl" by John Steinbeck

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

Like with rivers, estuaries and areas of the sea around Wales are protected for their important habitats and wildlife.

From BBC ● Jun. 24, 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

There are also concerns for the survival of migratory birds, many of which make stop-offs on Britain’s vast shorelines and estuaries.

From BBC ● Oct. 28, 2024

Although spawning occurs at sea, the young come into the estuaries and bays when a few weeks old to undergo successive molts and changes of form.

From "Silent Spring" by Rachel Carson

Related Words

• inlet
• waterway