reservoir
noun
res·er·voir
ˈre-zə-ˌvwär 
-zər-
-ˌvwȯr
-zər-
-ˌvwȯr
also -ˌvȯi
1
2
: an extra supply : reserve
3
a
: a host organism in which an infectious agent (such as a bacterium or virus) that is pathogenic for some other species lives and multiplies typically without damaging the host
Note: A reservoir serves as a source from which transmission of infection and outbreaks of disease can occur.
It is the white-footed mouse that serves as a natural reservoir host for the spirochete B. [Borrelia] burgdorferi. These mice carry the spirochete without any apparent harm to themselves, and it is through feeding on infected mice that the immature stages of the tick acquire the spirochete.—
Suzanne Clothier et al.
Suzanne Clothier et al.
also
: a nonliving thing (such as soil or water) in which an infectious agent lives and multiplies and which serves as a source of infection similar to a host organism
b
: a part of the body that harbors an infectious agent and serves as a source of reinfection or infection transmission
… vulvar or rectal reservoirs, which might increase risk for BV [bacterial vaginosis] recurrence.—Lisa E. Manhart et al.
compare carrier sense 5a, vector entry 1 sense 2a
Lisa E. Manhart et al.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.
Recent Examples on the Web
The Northern Sierra, whose watersheds flow to many of the state’s largest reservoirs, on Monday had a snowpack 97% of its historical average.
—Paul Rogers, The Mercury News, 10 Mar. 2025
In the spring, the snow melts and supplements local rivers and reservoirs to carry them through the dry summer months.
—Dan Perry, Newsweek, 28 Feb. 2025
SpaceX Data collected by orbiting satellites indicate reservoirs of ice may be present in the cold, dark interiors of polar craters that never see the light of the sun.
—William Harwood, CBS News, 26 Feb. 2025
Most of the controversy focuses on a small section, south of Bismarck, N.D., that crosses under a reservoir on the Missouri River.
—Jeff Brady, NPR, 24 Feb. 2025
See All Example Sentences for reservoir
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Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
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Paul Rogers, The Mercury News, 10 Mar. 2025
In the spring, the snow melts and supplements local rivers and reservoirs to carry them through the dry summer months.
—Dan Perry, Newsweek, 28 Feb. 2025
SpaceX Data collected by orbiting satellites indicate reservoirs of ice may be present in the cold, dark interiors of polar craters that never see the light of the sun.
—William Harwood, CBS News, 26 Feb. 2025
Most of the controversy focuses on a small section, south of Bismarck, N.D., that crosses under a reservoir on the Missouri River.
—Jeff Brady, NPR, 24 Feb. 2025
See All Example Sentences for reservoir
Cite this Entry
“Reservoir.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reservoir. Accessed 13 Mar. 2025.
Copy CitationKids Definition
reservoir
noun
res·er·voir
ˈrez-ə(r)v-ˌwär
-ə(r)v-ˌ(w)ȯr
-ə(r)v-ˌ(w)ȯr
1
: a place where something is kept in store
especially
: an artificial or natural lake where water is collected as a water supply
2
: an extra supply : reserve
3
: a living thing (as a fly or mouse) in which a parasite (as a bacterium) that is harmful to some other living thing lives and multiplies
Etymology
from French réservoir "place where something is kept in reserve," from reserver "to reserve, keep for future use"
Medical Definition
reservoir
noun
res·er·voir
ˈrez-ə(r)v-ˌwär
-ə(r)v-ˌ(w)ȯr
-ə(r)v-ˌ(w)ȯr
1
: a space (as an enlargement of a vessel or the cavity of a glandular acinus) in which a body fluid is stored
2
a
: a host organism in which an infectious agent (as a bacterium or virus) that is pathogenic for some other species lives and multiplies typically without damaging the host
Note: A reservoir serves as a source from which transmission of infection and outbreaks of disease can occur.
Wild rodents also constitute a reservoir of hantaviruses. The viruses are shed in urine, droppings, and saliva, and humans are mainly infected aerogenically by inhaling aerosols containing the virus.—Hilde Kruse et al., Emerging Infectious Diseases
Hilde Kruse et al., Emerging Infectious Diseases
also
: a nonliving thing (as soil or water) in which an infectious agent lives and multiplies and which serves as a source of infection similar to a host organism
b
: a part of the body that harbors an infectious agent and serves as a source of reinfection or infection transmission
… vulvar or rectal reservoirs, which might increase risk for BV [bacterial vaginosis] recurrence.—Lisa E. Manhart et al., Infectious Diseases in Obstetrics and Gynecology
carrier sense 1a, vector entry 1 sense 2
Lisa E. Manhart et al., Infectious Diseases in Obstetrics and GynecologyLove words? Need even more definitions?
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