reservoir

American  

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

noun

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.

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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

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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.

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Etymology

Origin of reservoir

1680–90; < French réservoir, equivalent to réserv ( er ) to reserve + -oir -ory ²

Example Sentences

In some older fields, the shock permanently alters reservoir dynamics, erasing some capacity forever.

From The Wall Street Journal • Apr. 8, 2026

"Craig was my mentor, wise counsel, passionate advisor, and great friend. He was the distinguished elder statesman with a reservoir of Olympic knowledge and experience which he shared willingly and to great effect," Coe added.

From BBC • Apr. 6, 2026

Seama says, "Due to its extent and location it is clear that this is in fact the same magma reservoir as in the previous eruption."

From Science Daily • Mar. 29, 2026

“But it’s not as ideal as having that additional snow reservoir ready to run off through summer, and replenish what we’re going to be releasing.”

From Los Angeles Times • Mar. 21, 2026

“Tree and Zheegwon, they were held by a colony of townspeople who tried different ways to extract their dreams, figuring they’d found some kinda personal reservoir with Indian twins.”

From "The Marrow Thieves" by Cherie Dimaline

Related Words

• basin
• cistern
• container
• lake
• pond
• pool
• reserve
• source
• stockpile
• storage
• supply
• tank