- any of a class of compounds containing chemically combined water. In the case of some hydrates, as washing soda, Na2CO3⋅10H2O, the water is loosely held and is easily lost on heating; in others, as sulfuric acid, SO3⋅H2O, or H2SO4, it is strongly held as water of constitution.
- to combine chemically with water.
Origin of hydrate
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for hydrate
Launching this spring, it promises “repair, hydrate and renew.”Michelle Obama wears Prabal Gurung; Melania Trump Wants You To Have Nice Skin
The Fashion Beast Team
October 19, 2012
The oxide and hydrate change to carbonate, and therefore are good.
“Milk of lime” consists of a cream of the hydrate and water.
Serpentine is a compound of silicate and hydrate of magnesium.
This hydrate is slightly soluble in water and reddens litmus.
An acid first obtained, by Plisson, from asparagin, by boiling it along with hydrate of lead or of magnesia.
- a chemical compound containing water that is chemically combined with a substance and can usually be expelled without changing the constitution of the substance
- a chemical compound that can dissociate reversibly into water and another compound. For example sulphuric acid (H 2 SO 4) dissociates into sulphur trioxide (SO 3) and water (H 2 O)
- (not in technical usage) a chemical compound, such as a carbohydrate, that contains hydrogen and oxygen atoms in the ratio two to one
- to undergo or cause to undergo treatment or impregnation with water
C19: from hydro- + -ate 1
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 hydrate
1802, "compound of water and another chemical," from French hydrate, coined c.1800 by French chemist Joseph-Louis Proust (1754-1826) from Greek hydr-, stem of hydor "water" (see water (n.1)).
Online Etymology Dictionary, © 2010 Douglas Harper
- A solid compound containing water molecules combined in a definite ratio as an integral part of a crystal.
- To rehydrate.
- To supply water to a person or thing in order to restore or maintain fluid balance.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- A compound produced by combining a substance chemically with water. Many minerals and crystalline substances are hydrates.
- To combine a compound with water, especially to form a hydrate.
- To supply water to a person in order to restore or maintain a balance of fluids.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.