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Synonyms

reservoir

American  
[rez-er-vwahr, -vwawr, -vawr, rez-uh-] / ˈrɛz ərˌvwɑr, -ˌvwɔr, -ˌvɔr, ˈrɛz ə- /

noun

  • reservoirs
    plural
  1. a natural or artificial place where water is collected and stored for use, especially water for supplying a community, irrigating land, furnishing power, etc.

  2. a receptacle or chamber for holding a liquid or fluid.

  3. Geology. pool16

  4. Biology. a cavity or part that holds some fluid or secretion.

  5. a place where anything is collected or accumulated in great amount.

    Synonyms:
    stockpile, fund, pool, store, hoard
  6. a large or extra supply or stock; reserve.

    a reservoir of knowledge.


reservoir British  
/ ˈrɛzəˌvwɑː /

noun

  1. a natural or artificial lake or large tank used for collecting and storing water, esp for community water supplies or irrigation

  2. a receptacle for storing gas, esp one attached to a stove

  3. biology a vacuole or cavity in an organism, containing a secretion or some other fluid

  4. anatomy another name for cisterna

  5. a place where a great stock of anything is accumulated

  6. a large supply of something; reserve

    a reservoir of talent

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

reservoir Scientific  
/ rĕz′ər-vwär′ /
  1. A natural or artificial pond or lake used for the storage of water.

  2. An underground mass of rock or sediment that is porous and permeable enough to allow oil or natural gas to accumulate in it.

  3. 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."

Keep Reading on Vocabulary.com

Vocabulary lists containing reservoir

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:

This year, the Rocky Mountains had the least snow on record, and the lack of snowmelt is sinking reservoir levels lower.

From Los Angeles Times ● Oct. 16, 2026

Speaking in the House of Commons, Hardy said the measures were down to "exceptional low rainfall" and depleted reservoir levels.

From BBC ● Oct. 16, 2026

Lake Mead, the largest reservoir in the United States, has plummeted to its lowest water level since it was filled some 90 years ago.

From Los Angeles Times ● Oct. 16, 2026

"The hydrogel acts as a local reservoir," Liu says.

From Science Daily ● Oct. 8, 2026

Annabeth grabbed my arm and pointed at the reservoir.

From "The Last Olympian" by Rick Riordan

The largest reservoirs, Lake Mead and Lake Powell, are at their lowest combined levels since Lake Powell began filling in 1963.

From The Wall Street Journal ● Oct. 16, 2026

But while AI could boost the efficiency and use of renewables, the technology has long been used by oil and gas companies to sift through geological data, identify underground reservoirs and streamline fossil fuel production.

From Barron's ● Oct. 15, 2026

According to Mr. Kean, the Indus Valley people specialized in big infrastructure projects, such as dams, reservoirs and early sewers that carried waste safely out of their settlements.

From The Wall Street Journal ● Oct. 14, 2026

It transports water across more than 700 miles with a series of reservoirs, aqueducts, pipelines and pumping plants from Northern California to Southern California.

From Los Angeles Times ● Oct. 9, 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

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