res·​er·​voir | \ ˈre-zə-ˌvwär How to pronounce reservoir (audio) , -zər-, -ˌvwȯr also -ˌvȯi How to pronounce reservoir (audio) \

Definition of reservoir

1 : a place where something is kept in store: such as
a : an artificial lake where water is collected and kept in quantity for use
b : a part of an apparatus in which a liquid is held
c : supply, store a large reservoir of educated people
2 : an extra supply : reserve
3 : an organism in which a parasite that is pathogenic for some other species lives and multiplies usually without damaging its host

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Examples of reservoir in a Sentence

The pen has a large ink reservoir. Colleges and universities provide reservoirs of talent for job recruiters. She found the reservoirs of energy she needed to finish the job.
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Recent Examples on the Web

The reservoir is empty most of the time, and its gates are open. Scott Dalton, CNN, "Their neighborhood was flooded to save Houston," 25 Aug. 2019 DeSantis also overturned leadership at the South Florida Water Management District after the board drew his ire by voting to grant a lease extension to Florida Crystals for land eyed by the Legislature for the Everglades Agricultural Area reservoir. Jim Turner,, "Gov. Ron DeSantis to clean water advocates: Keep pushing legislators on conservation issues," 22 Aug. 2019 Visitors are urged to not consume fish livers or digestive organs from fish caught in the reservoir. Erin Hardy,, "Health advisory issued for Duckett Reservoir in Laurel due to blue green algae," 21 Aug. 2019 The nonprofit Friends of Liberty Reservoir formed after residents expressed concerns about the condition of some of the roads at the reservoir. Jon Kelvey,, "Liberty Reservoir fire roads won’t be maintained or open to public after Baltimore decision; residents object," 16 Aug. 2019 The reservoirs were nearly full in 1999 before the agency declared a drought the following year that hasn’t let up. Washington Post, "Wet winter doesn’t end climate change risk to Colorado River," 15 Aug. 2019 That study found that sediment accumulated the most northwest of the Dallas Arboretum, where the reservoir narrows. Hayat Norimine, Dallas News, "'It's time': Dallas council member pushes for White Rock Lake dredging," 10 Aug. 2019 San Francisco city officials maintain that draining the reservoir is a terrible idea and could threaten the Bay Area’s water supply. Taylor Kate Brown,, "Bay Briefing: Say goodbye to plastic water bottles at SFO," 2 Aug. 2019 The reservoir also has a sandy swim beach, complete with lifeguards and a sand volleyball court. Sarah Kuta, The Know, "9 spots that are perfect for your next Colorado lake day," 1 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reservoir.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of reservoir

1690, in the meaning defined at sense 1

History and Etymology for reservoir

French réservoir, from Middle French, from reserver

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Statistics for reservoir

Last Updated

7 Sep 2019

Look-up Popularity

Time Traveler for reservoir

The first known use of reservoir was in 1690

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More Definitions for reservoir



English Language Learners Definition of reservoir

: a usually artificial lake that is used to store a large supply of water for use in people's homes, in businesses, etc.
: a place (such as a part of a machine) where a liquid is stored
: an extra supply of something


res·​er·​voir | \ ˈre-zər-ˌvwär How to pronounce reservoir (audio) \

Kids Definition of reservoir

: a place where something (as water) is kept in store for future use


res·​er·​voir | \ ˈrez-ə(r)v-ˌwär How to pronounce reservoir (audio) , -ə(r)v-ˌ(w)ȯr How to pronounce reservoir (audio) \

Medical Definition of reservoir

1 : a space (as an enlargement of a vessel or the cavity of a glandular acinus) in which a body fluid is stored
2 : an organism in which a parasite that is pathogenic for some other species lives and multiplies without damaging its host also : a noneconomic organism within which a pathogen of economic or medical importance flourishes without regard to its pathogenicity for the reservoir rats are reservoirs of plague — compare carrier sense 1a

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Comments on reservoir

What made you want to look up reservoir? Please tell us where you read or heard it (including the quote, if possible).


one from the Upper Peninsula of Michigan

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