fluid

From Middle English fluid, from Latin fluidus (“flowing; fluid”), from Latin fluō (“to flow”), from Proto-Indo-European *bʰleh₁- (“to swell; surge; overflow; run”). Akin to Ancient Greek φλύειν (phlúein, “to swell; overflow”). Not related to English flow, which is a native, inherited word from *plew-.

• (UK) IPA^(key): /ˈfluːɪd/, [ˈfluwɪd], /ˈflʊɪ̯d/
• (US) IPA^(key): /ˈfluːɪd/, [ˈfluwɪd]

• Audio (US)

  (file)

• Rhymes: -uːɪd

fluid (countable and uncountable, plural fluids)

1. Any substance which can flow with relative ease, tends to assume the shape of its container, and obeys Bernoulli's principle; a liquid, gas or plasma.
   • 2013 March 1, Frank Fish, George Lauder, “Not Just Going with the Flow”, in American Scientist‎, volume 101, number 2, page 114:

     An extreme version of vorticity is a vortex. The vortex is a spinning, cyclonic mass of fluid, which can be observed in the rotation of water going down a drain, as well as in smoke rings, tornados and hurricanes.

2. (specifically, medicine, colloquial, typically in the plural) Intravenous fluids.

• amber fluid
• brake fluid
• fluid mechanics

fluid (comparative more fluid, superlative most fluid)

1. (not comparable) Of or relating to fluid.
2. In a state of flux; subject to change.
   • 2013 August 3, “Boundary problems”, in The Economist, volume 408, number 8847:

     Economics is a messy discipline: too fluid to be a science, too rigorous to be an art. Perhaps it is fitting that economists’ most-used metric, gross domestic product (GDP), is a tangle too. GDP measures the total value of output in an economic territory. Its apparent simplicity explains why it is scrutinised down to tenths of a percentage point every month.

3. Moving smoothly, or giving the impression of a liquid in motion.
4. (of an asset) Convertible into cash.
5. (rare) Genderfluid.
   • 2017, Rick Riordan, Magnus Chase and the Hammer of Thor (→ISBN), page 274 (the genderfluid character Alex Fierro is speaking):

     “Oh, Loki made sure of that. My mortal parents blamed him for the way I was, for being fluid.”

• fluctuate
• fluency
• fluent
• flux
• fluidic
• fluidics
• fluidify
• fluidise
• fluidize
• fluidity
• fluidous
• semifluid

• fluid in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• fluid in The Century Dictionary, The Century Co., New York, 1911
• fluid at OneLook Dictionary Search

fluid (feminine fluida, masculine plural fluids, feminine plural fluides)

1. fluid

fluid m (plural fluids)

1. fluid

fluid (not comparable)

1. fluid

• flüssig

• fluid in Duden online

fluid n (definite singular fluidet, indefinite plural fluid or fluider, definite plural fluida or fluidene)

1. a fluid

• væske

• fluidmekanikk

• “fluid” in The Bokmål Dictionary.

fluid n (definite singular fluidet, indefinite plural fluid, definite plural fluida)

1. a fluid

• væske

• fluidmekanikk

• “fluid” in The Nynorsk Dictionary.

• IPA^(key): /flûiːd/
• Hyphenation: flu‧id

flȕīd m (Cyrillic spelling флу̏ӣд)

1. fluid

fluid

1. (Spain) Informal second-person plural (vosotros or vosotras) affirmative imperative form of fluir.