hydrate

American  

[hahy-dreyt] / ˈhaɪ dreɪt /

noun

1. any of a class of compounds containing chemically combined water. In the case of some hydrates, as washing soda, Na 2 CO 3 ⋅10H 2 O, the water is loosely held and is easily lost on heating; in others, as sulfuric acid, SO 3 ⋅H 2 O, or H 2 SO 4 , it is strongly held as water of constitution.

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verb (used with or without object)

hydrated, hydrating

1. to combine chemically with water.

hydrate British  

/ ˈhaɪdreɪt /

noun

1. a chemical compound containing water that is chemically combined with a substance and can usually be expelled without changing the constitution of the substance

2. 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)

3. (not in technical usage) a chemical compound, such as a carbohydrate, that contains hydrogen and oxygen atoms in the ratio two to one

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verb

1. to undergo or cause to undergo treatment or impregnation with water

hydrate Scientific  

/ hī′drāt′ /

1. A compound produced by combining a substance chemically with water. Many minerals and crystalline substances are hydrates.

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1. To combine a compound with water, especially to form a hydrate.

2. To supply water to a person in order to restore or maintain a balance of fluids.

Other Word Forms

• hydration
  noun
• hydrator
  noun

Etymology

Origin of hydrate

First recorded in 1795–1805; hydr- ¹ + -ate ²

Explanation

To hydrate is to add or absorb water. It's hot outside — don't forget to hydrate by drinking plenty of water! If you want to sound fancy, you can use the word hydrate every time you get a drink of water. Along with most organisms, we need to hydrate, or ingest water, to stay alive. This verb is also commonly used to mean "moisturize," as in "this magic cream will hydrate your skin like you won't believe!" As a noun, hydrate refers to a chemical compound that includes water molecules. A French chemist coined the noun in 1800 from the Greek hydor, "water."

Example Sentences

CAHILLANE: Capri Sun Hydrate is a more expensive cost of good because of the electrolytes and the innovation.

From The Wall Street Journal • May 6, 2026

Hydrate often so that they can be encouraged to do so too.

From Los Angeles Times • Jul. 26, 2023

The UK launch of Prime Hydrate in early 2022 prompted long queues, grappling shoppers, and even headfirst dives into supermarket shelves.

From BBC • May 22, 2023

“It’s going to be very hot and humid. Hydrate and stay in shaded areas,” said James Tomasini, a meteorologist in Uptown, New York.

From Seattle Times • Jul. 21, 2022

Fig. 45.—Action of Chloral Hydrate on the Responses of Leaf-stalk of Cauliflower Vibration of 25° at intervals of one minute.

From Response in the Living and Non-Living by Bose, Jagadis Chandra, Sir