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

Instead, the medical provider may just tell their patient to keep an eye on their symptoms, wait and hydrate.

From Los Angeles Times ● Jul. 24, 2026

“This is the world’s game ... we have to figure out how to help players at all levels and ages to have the ability to thermoregulate, hydrate, how to do it well.”

From Los Angeles Times ● Jul. 7, 2026

Fifa has implemented drinks breaks at the midway point in each half for every game in this World Cup to allow players to hydrate.

From BBC ● Jun. 11, 2026

Boo watched her go, shouting, “Don’t forget to hydrate at home! Pandavas are always hydrated!”

From "Aru Shah and the End of Time" by Roshani Chokshi

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

Developed by scientists at the University of Leeds, the saliva substitute is described as comparable to natural saliva in the way it hydrates the mouth and acts as a lubricant when food is chewed.

From Science Daily ● Nov. 20, 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

In addition, the team found that each of the three moons has the same hydrated mineral that the team has not been able to identify.

From Science Daily ● Aug. 14, 2026

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

Like other tour guides, Giusto always urges tourists to stay hydrated, wear a hat and sunscreen.

From BBC ● Aug. 4, 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

“Be smart—stay hydrated and keep your fuel up.”

From "The Running Dream" by Wendelin Van Draanen

"You need to be eating a balanced diet, training well, sleeping right, recovering well, hydrating – all of those things – before we add in all of the extras."

From BBC ● Aug. 20, 2026

After the analysis, she was able to pick from care packages, each with a different purpose, such as slowing aging, hydrating the skin, clarifying it or brightening it.

From Los Angeles Times ● Aug. 17, 2026

You’ve got to be hydrating well before that, he says.

From The Wall Street Journal ● Jul. 3, 2026

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

My cousin, who keeps urging me to add a hydrating serum with hyaluronic acid and vitamin C to my skincare regime.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith