Definition of fluid in US English:

fluid

noun

  • 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’
    • ‘I believe that by doing this it helps to drive all the vital fluids around the body.’
    • ‘The main aim of the treatment is to replace the lost fluids and electrolytes in the body.’
    • ‘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.’
    • ‘Gold can form soluble compounds with these substances and so the fluids will leach it out of rocks.’
    • ‘The fluids that precipitated the veins were a likely source for some of the iron that formed the hematite.’
    • ‘It can be used for febrile diseases where the heat is burning up the fluids of the body.’
    • ‘The bakery owners later gave up their lease after it emerged that the liquid had in fact been body fluids from the two men.’
    • ‘What is known is that it secretes prostatic fluid, one of the five main fluids that make up semen.’
    • ‘I was on a drip because obviously I had no fluids in my body, the only liquid was alcohol.’
    • ‘Large volumes of fluids may be infused, and these intravenous fluids should be warmed.’
    • ‘Replacing these lost fluids is essential if the body is to be kept in balance and dehydration avoided.’
    • ‘The main benefit from drinking toast water would, however, be the replacement of body fluids.’
    • ‘However, Hepatitis B is easily transmitted by contact with blood and other body fluids.’
    • ‘Aim to drink at least half of your daily fluids as water and other hydrating fluids.’
    • ‘Kochin's research was on meteorology, gas dynamics and shock waves in compressible fluids.’
    • ‘After condensation, the fluids are drawn back to the areas that are in need of cooling.’
    • ‘Intravenous fluids dramatically improved his condition and restored his body weight.’
    • ‘He found that more ion-rich pore fluids caused an increase in angle of friction.’
    • ‘Detectives later confirmed that the stains had been caused by body fluids.’
    flowing substance
    View synonyms

adjective

  • 1(of a substance) able to flow easily.

    ‘the paint is more fluid than tube watercolors’
    ‘a fluid medium’
    1. 1.1 Not settled or stable; likely or able to change.
      ‘our plans are still fluid’
      ‘the fluid political situation of the 1930s’
    2. 1.2 Smoothly elegant or graceful.
      ‘her movements were fluid and beautiful to watch’
    3. 1.3 (of a clutch or coupling) using a liquid to transmit power.

Origin

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

Pronunciation

fluid

/ˈflo͞oid//ˈfluɪd/