Meaning & use
estuary
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Meaning
nouncountable
The wide, tidal mouth of a river, where fresh water flowing down meets the salty water of the sea and the two mix.
Grammar: Has a plural: one estuary, several estuaries.
Patterns
- the estuary of something
- in the estuary
Thousands of wading birds feed on the mudflats of the estuary each winter.
The ferry crosses the estuary in about twenty minutes.
Because the water in an estuary is partly salty, it supports plants you will not find upstream.
Word forms
| plural | estuaries |
|---|
Common combinations
- river estuary
- The river estuary is more than two miles wide at high tide.
- tidal estuary
- Boats can only enter the tidal estuary when the water is high.
- estuary wetlands
- The estuary wetlands protect the town from storm surges.
- cross the estuary
- A long bridge lets drivers cross the estuary without a detour.
- at the mouth of an estuary
- The old fishing village sits at the mouth of the estuary.
Synonyms and how they differ
- firth
- Firth is the Scottish word for a long coastal inlet or river mouth, and it is used mainly in place names, whereas estuary is the general scientific term.
- river mouth
- River mouth only points to where a river ends, while estuary stresses the zone of mixed fresh and salt water.
- delta
- A delta is a fan of land built from deposited sediment, while an estuary is a funnel-shaped opening that the tide flows into.
Word family
- estuarine adjective
- relating to or found in an estuary
- estuarial adjective
- a less common variant of estuarine
Commonly confused: estuary or delta?
estuary vs delta
A delta is built up from river sediment and often splits into many channels; an estuary is a single tidal opening where river and sea water mix.
Practice
Salt marshes and mudflats surround the ____, where the river water mixes with the incoming tide.
Choose one answer.
An estuary is the tidal river mouth where fresh and sea water mix. A reservoir is a stored body of fresh water, so it does not fit the tide.
Make it your own
Write a sentence using “estuary”, then check it and compare it with the examples above.