Definition of fluid in English:



  • A substance that has no fixed shape and yields easily to external pressure; a gas or (especially) a liquid.

    ‘we all need several glasses of fluid a day’
    ‘a cleaning fluid’
    • ‘Kochin's research was on meteorology, gas dynamics and shock waves in compressible fluids.’
    • ‘The main benefit from drinking toast water would, however, be the replacement of body fluids.’
    • ‘Replacing these lost fluids is essential if the body is to be kept in balance and dehydration avoided.’
    • ‘Detectives later confirmed that the stains had been caused by body fluids.’
    • ‘I believe that by doing this it helps to drive all the vital fluids around the body.’
    • ‘However, Hepatitis B is easily transmitted by contact with blood and other body fluids.’
    • ‘Large volumes of fluids may be infused, and these intravenous fluids should be warmed.’
    • ‘The fluids that precipitated the veins were a likely source for some of the iron that formed the hematite.’
    • ‘The main aim of the treatment is to replace the lost fluids and electrolytes in the body.’
    • ‘He found that more ion-rich pore fluids caused an increase in angle of friction.’
    • ‘It can be used for febrile diseases where the heat is burning up the fluids of the body.’
    • ‘Gold can form soluble compounds with these substances and so the fluids will leach it out of rocks.’
    • ‘After condensation, the fluids are drawn back to the areas that are in need of cooling.’
    • ‘The bakery owners later gave up their lease after it emerged that the liquid had in fact been body fluids from the two men.’
    • ‘Intravenous fluids dramatically improved his condition and restored his body weight.’
    • ‘Aim to drink at least half of your daily fluids as water and other hydrating fluids.’
    • ‘I was on a drip because obviously I had no fluids in my body, the only liquid was alcohol.’
    • ‘What is known is that it secretes prostatic fluid, one of the five main fluids that make up semen.’
    • ‘Deep down within fluids or aquifers volatilization is not an important transport process.’
    • ‘These faults are presumably acting as pathways for the fluids involved in the formation of gas hydrates.’
    flowing substance
    liquid, watery substance, moisture, solution, juice, sap
    gas, gaseous substance, vapour
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  • 1(of a substance) able to flow easily.

    ‘the paint is more fluid than tube watercolors’
    ‘a fluid medium’
    • ‘Although adults do not drink a lot of fluid milk in China, an emerging audience may lie in young consumers.’
    • ‘Where was all this water coming from - as much ice as there was in the freezer it still couldn't have made this amount of fluid water surely.’
    • ‘We are also putting a lot of emphasis on our merchandising programs - both for ice creams and fluid milk.’
    • ‘Fill the space between tin can and saucepan with water and heat the whole contraption until the glue is fluid.’
    • ‘Innovations are not limited to a specific category, with subtle or bold changes evident in products from cultured products to ice cream to fluid milk.’
    • ‘Adding additional calcium to dairy formulations is an option and one currently adopted by processors of all sorts from cheese to ice cream to fluid milk.’
    • ‘Consequently, there may be a layer of fluid water around the chromophore that rearranges upon excitation.’
    • ‘It spilled out from her fingers in the form of a fluid silver substance and flooded the man's leg down to the marrow of his bone.’
    • ‘In addition to fluid milk, it markets a wide range of organic dairy products including buttermilk, whipping cream and a dozen kinds of cheese.’
    • ‘Miro, Louis and Poons showed the strikingly different effects that could be obtained by pouring a fluid substance down a canvas.’
    • ‘The late afternoon sun shimmers on the Hudson River, creating a blinding surface of fluid silver that coats the dull green.’
    • ‘Place bowl back over water and stir until chocolate is fluid again and thermometer reads approximately 100 degrees.’
    • ‘Melt real dark chocolate in a nonstick pan and beat in just enough full-fat milk for a gloopy, fluid drink.’
    • ‘The company pasteurized its first gallon of fluid milk in January 1946 and began ice cream production two years later.’
    • ‘Material is pumped from the sea bed as a fluid mixture with water and is discharged into the dredger's hoppers where the heavy material rapidly sinks to the bottom.’
    • ‘The addition of crop oil, surfactant, or fluid fertilizer may improve control of emerged weeds.’
    • ‘Children who are lactose intolerant can often consume fermented milk products like cheese and yogurt as well as lactose-free fluid milk.’
    • ‘‘He has achieved this by using increasingly fluid paint, which can be floated over large areas or deployed in a much more linear way,’ says Terry.’
    • ‘Even though they are working in a fluid substance, they have several things in their favour in comparison to swimmers.’
    • ‘As if to pour salt into the wound that is the declining sale of fluid milk, sales of soy beverages are soaring.’
    flowing, able to flow easily
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    1. 1.1Not settled or stable; likely or able to change.
      ‘our plans are still fluid’
      ‘the fluid political situation of the 1930s’
      • ‘Of course, this is only one news report in a highly fluid situation, creating the risk that I may be forced to eat my words before Monday.’
      • ‘The situation will be fluid for six months, or at least until Parliament resumes.’
      • ‘We now also have a much more fluid political situation.’
      • ‘But as I noted recently, the situation is now extremely fluid.’
      • ‘However, what is impossible within the fixed boundaries of political organisations may be more plausible in the far more fluid world of political ideas.’
      • ‘But I want to be careful and say that this is such a fluid situation, Larry.’
      • ‘But the situation was fluid, and individual commanders had a lot of leeway.’
      • ‘I'm just reminded that political definitions are fluid, and shift with the times.’
      • ‘I believe in a more fluid kind of political change: you throw an idea out there and it travels, and it changes.’
      • ‘In general one of the good effects (see, I do admit there are some) of the Euro will be to make prices in the Eurozone more fluid and hence to settle at a generally lower level in the long run.’
      • ‘The devolution ‘settlement’ is becoming less settled and more fluid.’
      • ‘Now, you can still kill the enemy, and in fluid situations where someone may or may not be a prisoner, you can still act to defend yourself.’
      • ‘Military developments have overtaken political events, making the situation in Afghanistan dangerously fluid.’
      • ‘But I want everyone to understand, this is a very fluid situation.’
      • ‘This is a very fluid political situation in a very unusual state.’
      • ‘Balanced between neoclassicism and romanticism, the composition appears at once rigidly stable yet inherently fluid.’
      • ‘So yes, the political situation might be rather fluid, even on Olympus.’
      • ‘The situation is still very fluid, and it's hard to tell whether the U.S. concept of the operation will be successful.’
      • ‘The result is a fluid political situation complicated by international relationships, cultural values, and divergent goals.’
      • ‘Clearly the political situation is very fluid and we can expect the contest for middle NZ to get even more competitive.’
      adaptable, flexible, adjustable, open-ended, open, open to change, changeable, not fixed, not settled, variable, versatile
      fluctuating, changeable, likely to change, subject to change, unsteady, shifting, ever-shifting, mobile, inconstant
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    2. 1.2Smoothly elegant or graceful.
      ‘her movements were fluid and beautiful to watch’
      • ‘Last but not the least is the ‘Bridal Wear’ collection with long, fine, fluid lines and graceful volumes in rich luxurious crepe and silks.’
      • ‘Every movement of the officer's hand was so fluid, so graceful.’
      • ‘There is an easy elegance here, a fluid readability, and a lucid, completely unaffected, eloquence of one who is at ease with herself.’
      • ‘A more weighty tripod will feel more secure and give smoother, more fluid use.’
      • ‘With its understated elegant designs and fluid lines, the collection should appeal to both traditional and contemporary tastes.’
      • ‘What was once erratic was now fluid and graceful.’
      • ‘Arlan did indeed remember that dance, of how fluid and graceful she'd felt in his arms.’
      • ‘Pausing only to throw my BBC notepad and pen to one side, I storm over the human hurdles in what I imagine to be a graceful, fluid study in perfect technique.’
      • ‘Christopher fought with a fluid elegance, every move graceful and balanced.’
      • ‘With quick acceleration and a smooth, fluid stride, Holt can run by most defenders.’
      • ‘With the fluid smoothness that comes only after thousands of repetitions, I mounted the gun when the flight was 40 yards out.’
      • ‘The English is fairly fluid although not altogether smooth in places.’
      • ‘Audrey tried her hardest to be fluid, to be graceful, but walking wasn't half so easy as dancing.’
      • ‘The cinematography was wonderful and the direction was fluid and elegant, surprisingly so considering the subject.’
      • ‘The juggling and rope acts were hypnotic; the costume, staging and music are all original and often beautiful; the performances fluid and graceful.’
      • ‘He was so fluid and so graceful and I couldn't tear my eyes away from him, I just couldn't!’
      • ‘The colors are rich and saturated, and the signature camera moves are fluid and elegant as usual.’
      • ‘While there are many transitions and sections in each song, this record is so fluid and slippery smooth it often recalls a state of lucid dreaming.’
      • ‘But ever since women became interested in breakdancing, they've brought a new way of moving to it - more angular, graceful and fluid, and more feminine.’
      • ‘It still has an elegant and fluid design, understated rather than flash, but sadly it is missing the distinctive boomerang-shaped rear lights.’
      free-flowing, flowing, fluent, smooth, effortless, easy, natural, unbroken, uninterrupted, continuous
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    3. 1.3(of a clutch or coupling) using a liquid to transmit power.
      • ‘Broadly, fluid couplings are of two types - constant and variable speed.’


Late Middle English (as an adjective): from French fluide or Latin fluidus, from fluere to flow.