reservoir
Americannoun
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reservoirs
plural
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a natural or artificial place where water is collected and stored for use, especially water for supplying a community, irrigating land, furnishing power, etc.
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a receptacle or chamber for holding a liquid or fluid.
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Geology. pool16
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Biology. a cavity or part that holds some fluid or secretion.
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a place where anything is collected or accumulated in great amount.
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a large or extra supply or stock; reserve.
a reservoir of knowledge.
noun
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a natural or artificial lake or large tank used for collecting and storing water, esp for community water supplies or irrigation
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a receptacle for storing gas, esp one attached to a stove
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biology a vacuole or cavity in an organism, containing a secretion or some other fluid
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anatomy another name for cisterna
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a place where a great stock of anything is accumulated
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a large supply of something; reserve
a reservoir of talent
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A natural or artificial pond or lake used for the storage of water.
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An underground mass of rock or sediment that is porous and permeable enough to allow oil or natural gas to accumulate in it.
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An organism that is the host for a parasitic pathogen or that directly or indirectly transmits a pathogen to which it is immune.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of reservoir
1680–90; < French réservoir, equivalent to réserv ( er ) to reserve + -oir -ory 2
Explanation
The word reservoir refers to a place where large amounts of water get stored. It can also be used to describe great amounts of other things, such as when you refer to a trivia expert as a reservoir of useless knowledge. The word reservoir comes from the French réservoir, which further derives from the Old French reserver, meaning "to reserve." Knowing this, it makes sense that the meaning evolved into a place, either man-made or natural, where water is stored or "reserved," usually for distribution for drinking, irrigating, and generating power. Remembering the related word reserve might also help in both the spelling and pronunciation of the word, as reserve is spelled (and pronounced) with "er," the same as "reservoir."
Vocabulary lists containing reservoir
Persepolis
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Africa - Introductory
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The Water Cycle - Introductory
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Officials channeled water into Powell from an upstream reservoir and cut planned releases from the lake by 20%.
From The Wall Street Journal ● Aug. 16, 2026
The plans include a short-term fix for an ailing reservoir and longer-term efforts to keep the river flowing.
From The Wall Street Journal ● Aug. 16, 2026
The massive reservoir was at risk of falling below levels needed to generate hydropower.
From The Wall Street Journal ● Aug. 16, 2026
Five are exceptionally low - among them Clywedog reservoir in Powys which provides water supplies for parts of the West Midlands.
From BBC ● Aug. 10, 2026
Some found the sewer and some worked their way up the hill to the reservoir and some went into culverts and some only hid among the weeds in the vacant lot.
From "Cannery Row" by John Steinbeck
But drought and overuse have drained its reservoirs.
From The Wall Street Journal ● Aug. 16, 2026
From historic sites and parks to reservoirs and golf courses, the hot, dry weather has changed how large parts of the UK usually look.
From BBC ● Aug. 10, 2026
The two reservoirs near the center of the image were among the areas hit hardest.
From Science Daily ● Aug. 5, 2026
In mid-July, the combined water levels of Lake Powell and Lake Mead, the two largest reservoirs in the United States and both fed by the Colorado River, reached their lowest levels in over 60 years.
From Barron's ● Jul. 31, 2026
Kaan itself dug out a series of reservoirs, established neighborhoods around each one, and linked the ensemble with roads and waterways.
From "1491" by Charles C. Mann
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
