[ rez-er-vwahr, -vwawr, -vawr, rez-uh- ]
See synonyms for reservoir on
  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.

  1. Geology. See under pool1 (def. 6).

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

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

  4. a large or extra supply or stock; reserve: a reservoir of knowledge.

Origin of reservoir

1680–90; <French réservoir, equivalent to réserv(er) to reserve + -oir-ory2

Other words for reservoir

Words Nearby reservoir Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use reservoir in a sentence

British Dictionary definitions for reservoir


/ (ˈrɛzəˌvwɑː) /

  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

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

  2. anatomy another name for cisterna

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

  4. a large supply of something; reserve: a reservoir of talent

Origin of reservoir

C17: from French réservoir, from réserver to reserve

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

Scientific definitions for reservoir


[ rĕzər-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.

  1. An organism that is the host for a parasitic pathogen or that directly or indirectly transmits a pathogen to which it is immune.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.