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.

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

Related Words for dehydrate

dry, drain, sear, parch, evaporate, exsiccate, desiccate

Examples from the Web for dehydrate

Historical Examples of 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

dehydrate in Medicine




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.