fluidity

American  

[floo-id-i-tee] / fluˈɪd ɪ ti /

noun

1. the quality or state of being fluid.

2. Physics.

   1. the ability of a substance to flow.

   2. a measure of this ability, the reciprocal of the coefficient of viscosity.

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fluidity British  

/ fluːˈɪdɪtɪ /

noun

1. the state of being fluid

2. physics the reciprocal of viscosity

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Other Word Forms

• nonfluidity
  noun

Etymology

Origin of fluidity

First recorded in 1595–1605; fluid + -ity

Explanation

Fluidity is a quality of being graceful or flowing, like the fluidity of a dancer's movements. Things that move with easy, smooth motions have fluidity — think of clouds moving across the sky on a windy day, or the way a modern dancer's body moves. This adjective can also mean "changeable," like the fluidity of ideas being exchanged during a high school debate class. As a physical quality, you might also describe the fluidity of any substance that's fluid, or behaves like a liquid.

Example Sentences

The fluidity of the situation in the Middle East is a wildcard for Singapore’s economy.

From The Wall Street Journal • May 26, 2026

“By being called ‘member of technical staff,’ there can be more fluidity of engineers doing more research work, researchers writing more code, or people going in between.

From MarketWatch • May 9, 2026

US Defence Secretary Pete Hegseth has appeared to suggest that there could be a tactical advantage to the apparent fluidity.

From BBC • Apr. 3, 2026

These shifts between stiffness and fluidity play a central role in enabling division.

From Science Daily • Feb. 28, 2026

Something in the way the tennis players hold themselves, or the way they toss the ball, or the fluidity of their motion triggers something in his unconscious.

From "Blink" by Malcolm Gladwell