Definition of fluid in English:

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Pronunciation: /ˈfluːɪd/


A substance that has no fixed shape and yields easily to external pressure; a gas or (especially) a liquid: body fluids [mass noun]: a bottle of cleaning fluid
More example sentences
  • Gold can form soluble compounds with these substances and so the fluids will leach it out of rocks.
  • The bakery owners later gave up their lease after it emerged that the liquid had in fact been body fluids from the two men.
  • I was on a drip because obviously I had no fluids in my body, the only liquid was alcohol.
flowing substance;
liquid, watery substance, moisture, solution, juice, sap;
gas, gaseous substance, vapour


1(Of a substance) able to flow easily: the paint is more fluid than tube watercolours
More example sentences
  • 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.
  • Miro, Louis and Poons showed the strikingly different effects that could be obtained by pouring a fluid substance down a canvas.
  • 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.
flowing, able to flow easily;
liquid, liquefied, melted, molten, uncongealed, running;
gaseous, gassy
technical fluxional
1.1Smoothly elegant or graceful: her movements were fluid and beautiful to watch
More example sentences
  • The juggling and rope acts were hypnotic; the costume, staging and music are all original and often beautiful; the performances fluid and graceful.
  • Christopher fought with a fluid elegance, every move graceful and balanced.
  • There is an easy elegance here, a fluid readability, and a lucid, completely unaffected, eloquence of one who is at ease with herself.
free-flowing, flowing, fluent, smooth, effortless, easy, natural, unbroken, uninterrupted, continuous;
graceful, elegant;
regular, rhythmic
1.2Not settled or stable; likely or able to change: our plans are still fluid the fluid political situation of the 1930s
More example sentences
  • This is a very fluid political situation in a very unusual state.
  • We now also have a much more fluid political situation.
  • I'm just reminded that political definitions are fluid, and shift with the times.
adaptable, flexible, adjustable, open-ended, open, open to change, changeable, not fixed, not settled, variable, versatile
fluctuating, changeable, subject/likely to change, unsteady, shifting, ever-shifting, mobile, inconstant;
unstable, unsettled, turbulent, volatile, mercurial, protean, kaleidoscopic, knife-edge, explosive
2(Of a clutch or coupling) using a liquid to transmit power.
Example sentences
  • Broadly, fluid couplings are of two types - constant and variable speed.



Example sentences
  • The song was slow and smooth and Simba danced fluidly yet unpredictably.
  • When filming, you had to creep smoothly, fluidly along so that the camera detected no bobbing motion.
  • But not everyone would be able to slide from bottom-space to performance mode as fluidly as Jae does.


Pronunciation: /-ˈɪdɪfʌɪ/




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

Words that rhyme with fluid

Clwyd, Druid

For editors and proofreaders

Line breaks: fluid

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