Definition of hydrate in English:



Pronunciation /ˈhʌɪdreɪt/
  • A compound, typically a crystalline one, in which water molecules are chemically bound to another compound or an element.

    • ‘Gas hydrate is a crystalline substance composed of gas and water.’
    • ‘Methane hydrates belong to a group of compounds known as gas hydrates.’
    • ‘The two most stable species of phosphates are the two extremes of hydrates, the anhydrous salt and the fully hydrated salt.’
    • ‘Methane hydrate is an ice-like compound in which methane molecules are enclosed in cavities formed by water molecules.’
    • ‘Most of the remainder comes from wetlands, gas hydrates, permafrost, and termites.’


[with object]
Pronunciation /hʌɪˈdreɪt/
  • 1Cause to absorb water.

    ‘a powerful moisturizer that hydrates the skin for up to twelve hours’
    • ‘And I do have unlimited bottled water and orange juice here with which to hydrate myself.’
    • ‘Replenish moisture lost during the super-cleansing by hydrating your skin thoroughly.’
    • ‘The skin is constantly hydrated and has protection against line-producing dehydration.’
    • ‘The chicken feet are first blanched with boiling water to hydrate the skin.’
    • ‘Rub the sachet over your entire body to cleanse and hydrate dry skin.’
    • ‘This not only hydrates the plant but settles the soil close to the roots, getting rid of any air pockets.’
    • ‘First spray on a little water to hydrate your skin.’
    • ‘On their own they will not have a huge impact on symptoms, but they will help to reduce the appearance of scale and redness, they help to hydrate the skin and can soothe itch if present.’
    • ‘Water not only hydrates, but it also can increase your blood volume to help make you stronger when you train.’
    • ‘The great thing is that it hydrates and protects your skin without leaving your face looking oily.’
    • ‘Facial moisturizers help hydrate the skin on your face.’
    • ‘All that water you downed hydrates your skin, making your cheeks rosy and eyes bright - bonus!’
    • ‘While I was still tingling from that experience a steam mask was put over my face to deep clean my pores and to hydrate my skin further.’
    • ‘The treatment is supposed to hydrate skin immediately, making the face appear smoother and plumper.’
    • ‘The essential oils of palmarosa, jasmine, sandalwood, and orange blossom hydrate the face to help hold in natural moisture.’
    • ‘These are usually emollients, which soothe, smooth and hydrate the skin.’
    • ‘Moisturise and hydrate skin thoroughly before going to bed.’
    • ‘This one is really good for dry skin, this one hydrates your skin, what do you want it for?’
    • ‘When training in hot weather, you need to systematically hydrate your body properly.’
    • ‘It hydrates the child throughout the day and gives them the various vitamins and minerals that will help sustain their concentration at school.’
    1. 1.1Chemistry Combine chemically with water molecules.
      ‘hydrated silicate crystals’
      • ‘All ions in solution are hydrated, surrounded by water molecules that bond to it through ionic attractions.’
      • ‘Sections were dewaxed in xylene and hydrated in ethanol.’
      • ‘When an ionic solute is dissolved in water equilibrium is established between the solid phase and the various hydrated ionic species.’
      • ‘Water bridges represent the most economical way to hydrate the surface of molecules, with an associated entropic cost.’
      • ‘Caesium is a weakly hydrated alkaline metal with chemical similarities to potassium.’


Early 19th century: coined in French from Greek hudōr ‘water’.