verb (used with object), de·hy·drat·ed, de·hy·drat·ing.

to deprive (a chemical compound) of water or the elements of water.
to free (fruit, vegetables, etc.) from moisture for preservation; dry.
to remove water from (the body or a tissue).
to deprive of spirit, force, or meaning; render less interesting or effectual.

verb (used without object), de·hy·drat·ed, de·hy·drat·ing.

to lose water or moisture: Milk dehydrates easily.

Nearby words

  1. dehumanize,
  2. dehumidifier,
  3. dehumidify,
  4. dehydrase,
  5. dehydratase,
  6. dehydration,
  7. dehydrator,
  8. dehydro-,
  9. dehydrochlorinase,
  10. dehydrochlorinate

Origin of dehydrate

First recorded in 1850–55; de- + hydrate

Synonym study

2. See evaporate. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for dehydrate

British Dictionary definitions for dehydrate



to lose or cause to lose water; make or become anhydrous
to lose or cause to lose hydrogen atoms and oxygen atoms in the proportions in which they occur in water, as in a chemical reaction
to lose or deprive of water, as the body or tissues
Derived Formsdehydration, noundehydrator, noun

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

Word Origin and History for dehydrate



1854, from de- + hydrate (v.). A chemical term at first, given a broader extension 1880s. Related: Dehydration (1834).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for dehydrate




To remove water from; make anhydrous.
To preserve by removing water from something, such as vegetables.
To deplete the bodily fluids of an individual.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.