hydrate

American  

[hahy-dreyt] / ˈhaɪ dreɪt /

noun

• hydrates
  plural

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)

• hydrates,
  present (3rd person singular)
• hydrated,
  past participle,  past
• hydrating
  present participle

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

Derived Forms

• hydration
  noun
• hydrator
  noun

Inflected Forms

Nouns

• hydrates
  plural

Participles

• hydrating
  present
• hydrated
  past

Conjugated Forms

Present

• hydrate
  simple
• hydrates
  simple
• have hydrated
  perfect
• has hydrated
  perfect
• am hydrating
  progressive
• are hydrating
  progressive
• is hydrating
  progressive
• have been hydrating
  perfect progressive
• has been hydrating
  perfect progressive

Past

• hydrated
  simple
• had hydrated
  perfect
• was hydrating
  progressive
• were hydrating
  progressive
• had been hydrating
  perfect progressive

Future

• will hydrate
  simple
• will have hydrated
  perfect
• will be hydrating
  progressive
• will have been hydrating
  perfect progressive

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

See Examples For:

hydrate hydrates hydrated hydrating

The word hydrate means that water molecules are built into the material's structure.

From Science Daily ● Aug. 1, 2026

"You could run into the extremes of eating too much, where if you're not drinking enough water to hydrate and exceed the amount of soluble and insoluble fiber, you can get constipated," Lee said.

From Science Daily ● Mar. 8, 2026

By the time of her death she was refusing to drink, despite desperate efforts to hydrate her, and the inquest was told this was sign of hydrophobia, a fear of water commons in rabies cases.

From BBC ● Mar. 5, 2026

Make sure you hydrate before, during and after the show.

From Los Angeles Times ● Sep. 3, 2025

I wondered if it was wise to work up a sweat playing soccer/non-American football if you couldn’t hydrate after.

From "Darius the Great Is Not Okay" by Adib Khorram

Methanol helps prevent freezing and the accumulation of solid hydrates that can plug gas-compression equipment and limit pipeline flow, and it acts as a solvent and corrosion inhibitor.

From The Wall Street Journal ● Nov. 21, 2025

The bottom line is water is essential, hydrates us and has countless other health benefits.

From Salon ● Sep. 3, 2024

The challenge now is making sure everyone hydrates well to recover as quickly as possible.

From Washington Times ● Dec. 29, 2023

Researchers have previously studied how changes in bottom water temperature near continental margins can affect the release of methane from hydrates.

From Science Daily ● Dec. 6, 2023

These substances are the hydrates of the so-called alkaline metals, and may be compared to water in which part of the hydrogen is replaced by a metallic radicle.

From The New Gresham Encyclopedia. Vol. 1 Part 3 Atrebates to Bedlis by Various

Despite the upcoming relief in SoCal, weather officials urge residents to remain vigilant throughout the week and stay hydrated.

From Los Angeles Times ● Aug. 10, 2026

"Move immediately to a cool place, such as a designated cooling centre or a shaded area, and stay hydrated while resting," it advised.

From Barron's ● Aug. 2, 2026

The hydrated material stored far more charge, charged much faster, and continued to perform reliably for more than 400 charge cycles.

From Science Daily ● Aug. 1, 2026

What’s more, staying hydrated helps flush toxins, keeps organs functioning optimally and thins mucus, making it easier for lungs to stay clear.

From The Wall Street Journal ● Jul. 23, 2026

On one website, we find a list of supplies every dog walker should own: a spare leash, lots of baggies, and a reusable water bottle and plastic bowl to keep the dogs hydrated.

From "A Soft Place to Land" by Janae Marks

The fruit is also made up of about 92% water, making it a hydrating option during hot weather or after exercise.

From Science Daily ● May 17, 2026

Protein loading, for example, can damage kidneys if you aren’t checking levels or hydrating well enough, says Talib.

From The Wall Street Journal ● May 4, 2026

Chen fitted me with what looked like an enormous diving mask that quickly filled with cool, hydrating mist — I felt droplets of water dripping from my eyes and down my cheeks.

From Los Angeles Times ● Apr. 6, 2026

That brief chill allows the fat to firm and the panade to finish its quiet work, hydrating and binding.

From Salon ● Mar. 11, 2026

She produced an oblong cake of soap in a black case, a hydrating mask, a vial of cell renewal drops, and two tubes of face cream.

From "Interpreter of Maladies" by Jhumpa Lahiri