English Reference
noun · verb

reservoir

n. · v.
US /ˈɹɛzəvˌwɑɹ/ UK /ɹˈɛzəvwˌɑː/ reser·voir UK spelling reservoir's, reservoir's, reservoired

  1. 01 B2 Upper Intermediate

    n.a large natural or artificial lake used to store water for a city or region.

    n.a large natural or artificial lake used as a source of water supply for domestic, industrial, or agricultural use.

    Simple

    The city built a new reservoir in the hills to ensure there was enough water during the dry summer.

    In context

    Following the prolonged drought, the water level in the main reservoir dropped to its lowest point since the dam was constructed forty years ago.

  2. 02 C1 Advanced Formal

    n.a large amount or source of something, like knowledge, energy, or feelings.

    n.a large supply or source of something, often used figuratively for abstract qualities or resources.

    Simple

    She has a deep reservoir of patience when dealing with difficult customers.

    In context

    The researcher tapped into a vast reservoir of historical data that had previously been overlooked by the academic community.

  3. 03 C2 Proficiency Technical Medicine

    n.a person or animal that carries a disease without getting sick, allowing the disease to survive and spread.

    n.a population or species that serves as a host for a pathogen, maintaining it over time and potentially transmitting it to other species.

    Simple

    Scientists believe that certain types of bats act as a reservoir for the virus.

    In context

    Identifying the animal reservoir is a critical step in preventing the spillover of zoonotic diseases into human populations.

  4. 04 C2 Proficiency Technical Computing

    n.a part of a computer system that processes signals in a complex way.

    n.a fixed, usually non-linear dynamical system used to map input signals into a high-dimensional space in reservoir computing.

    Simple

    The reservoir in this neural network helps process data more efficiently.

    In context

    In reservoir computing, the internal states of the reservoir are sampled and mapped to the desired output through a trained linear layer.

  5. 05 C2 Proficiency FormalTechnical

    v.to keep or store something in a large supply.

    v.to store or accumulate something in or as if in a reservoir. Transitive use is less common than the noun form.

    Simple

    The system is designed to reservoir excess energy during the day for use at night.

    In context

    The geological formation has the capacity to reservoir significant quantities of natural gas beneath the cap rock.

    distributedeplete

So we are acting now: more money into farm support, help to get reservoirs built and easier access to water when it is scarce.

The Guardian· 14 Aug 2026

Our three main sources of water are rivers, reservoirs and from deep underground.

BBC News· 7 Aug 2026

From French réservoir (“collection place”) (fig.), réservoir (“storehouse”) (lit.). in turn from French réserver (“to reserve, keep”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin French réserver
Level B2 · Upper Intermediate
Frequency Frequent
Updated