fluid

play

adjective flu·id \ ˈflü-əd \

Definition of fluid

1 a :having particles that easily move and change their relative position without a separation of the mass and that easily yield to pressure :capable of flowing

a long screw that forces the fluid chocolate through fine openings
—Technical Survey

b :subject to change or movement

boundaries became fluid

2 :characterized by or employing a smooth easy style

the ballerina's fluid movements

fluid recitation of his lines

3 a :available for various uses

a fluid computer program

b :liquid 4

fluid assets

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fluidly

adverb

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fluidness

noun

See fluid defined for English-language learners

See fluid defined for kids

Examples of fluid in a Sentence

a substance in a fluid state
warm the jam until it is fluid, then spread it over the cake

Recent Examples of fluid from the Web

The size of this group is fluid, depending on things like vacations, work and school schedules.

— david lyman, Cincinnati.com, "Ky. club offers comfortable place to learn English," 25 Aug. 2017
If his nostrils aren’t clogged, Chuck Schumer should be getting a whiff of vital fluid right now.

— eric levitz, Daily Intelligencer, "Trump Threatens to Shut Down the Government If He Doesn’t Get a Border Wall," 23 Aug. 2017
Above-neck seaside sensibilities were given an after dark guise, glossy bedhead traded for a slightly straighter iteration, golden lengths blown out to center on a soft and fluid wave.

— calin van paris, Vogue, "Gisele Bündchen's Secret for Making Her Legs Look Even Longer," 17 Aug. 2017
Those are also the odds of having a miscarriage from amniocentesis, a diagnostic test for chromosomal abnormalities (including Down syndrome) that takes fluid with a needle from the amniotic sac that surrounds the baby, Dr. Streicher explains.

— korin miller, Glamour, "Does It Really Matter If You Have Kids After 35?," 27 July 2017
This is a much different, much more fluid league from when Edsall left the Big East after 12 years for Maryland following the 2010 UConn season.

— jeff jacobs, courant.com, "Jeff Jacobs: Straight-Shooter Edsall Is Back, And No Doubt He’s In Charge," 19 July 2017
The first mapped fluid movements within an animal, by injecting it with a fluorescent dye and following the dye around.

— The Economist, "Sea spidersHow does an animal with no heart circulate oxygen?," 13 July 2017
Hardaway is expected to make the Knicks younger, more athletic and more fluid.

— mike vorkunov, New York Times, "It’s Official: Tim Hardaway Jr. Is Back With the Knicks," 8 July 2017
The interaction was more fluid than that of Putin and British Prime Minister Theresa May, who leaned awkwardly toward the Russian leader for a quick hand clasp across the table.

— michael birnbaum, Washington Post, "Breaking down the Putin-Trump handshake at the G-20 summit," 7 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fluid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of fluid

French or Latin; French fluide, from Latin fluidus, from fluere to flow; akin to Greek phlyzein to boil over

NEW! Time Traveler

First Known Use: 1603

See Words from the same year

fluid Synonyms

Synonyms

flowing, fluent, liquid

Antonyms

hard, nonliquid, solid

Related Words

circumfluent, circumfluous; diluted, thin, watery, weak; semiliquid, semisolid

Near Antonyms

clotted, coagulated, gelatinous, gelled, jelled, jellied, thick; gluey, glutinous, gooey, gummy, viscous

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous

fluid

noun

Definition of fluid

:a substance (such as a liquid or gas) tending to flow or conform to the outline of its container

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fluidal

play \ˈflü-ə-dᵊl\ adjective

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fluidally

play \ˈflü-ə-dᵊl-ē\ adverb

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fluidlike

play \ˈflü-ə-dᵊl-ˌlīk\ adjective

See fluid defined for English-language learners

Examples of fluid in a Sentence

Please check the fluids in the car's engine.
She needs to drink plenty of fluids.
Fluid leaked from the car's engine.
a bottle of yellow fluid

Recent Examples of fluid from the Web

The country is a hotbed of coals that's one splash of lighter fluid away from burning down, but Swift is obsessed with the one shiny object that can hold her attention: Taylor Swift.

— jeffrey lee puckett, The Courier-Journal, "Someone made Taylor Swift put out a terrible song, or maybe it's just her fault," 25 Aug. 2017
A flaw in the hydraulic-fluid cooling system, located in the fuel tanks, may cause the temperature of the liquid to rise quickly, the EASA said in an emergency airworthiness directive that took effect Thursday.

— richard weiss, Bloomberg.com, "Airbus A350s Require Overheating Fix, Aviation Regulator Says," 24 Aug. 2017
Sporting KC, 9-4-9, displayed fluid, free-moving spells with Diego Rubio connecting the top of the formation.

— sam mcdowell, kansascity, "No Dom? No problem. Sporting KC beats Chicago 3-2 in first match after Dwyer trade," 29 July 2017
These in turn depend on development of brain imaging tests or biomarkers that could be measured in the blood or other body fluids to allow a diagnosis of the disease in living people.

— meredith wadman, Science | AAAS, "Ninety-nine percent of ailing NFL player brains show hallmarks of neurodegenerative disease, autopsy study finds," 25 July 2017
Between 1837 and 1913 almost twice as many women as men stood trial at the Old Bailey for throwing a corrosive fluid, according to research by Katherine Watson of Oxford Brookes University.

— The Economist, "New fears, old menaceAcid attacks have a long history in Britain," 20 July 2017
If the fluid doesn’t get cleaned, Salas said, there’s a higher risk for developing Alzheimer’s disease or dementia.

— john kelly, Washington Post, "Snooze you can use: Sleep is important, so dreams must be, too, right?," 12 July 2017
The cardiac analogy is more than skin deep because a tunicate, like a heart, is all about pumping fluid.

— jennifer frazer, Scientific American Blog Network, "Alien Creature Swarming Oregon's Coast Is Actually a Close Relative [Video]," 10 July 2017
The participants answered questions about their sleep quality, and also provided samples of spinal fluid.

— amanda macmillan, Health.com, "The Powerful Way Getting a Good Night's Sleep May Protect Your Brain," 6 July 2017

Origin and Etymology of fluid

see ¹fluid

NEW! Time Traveler

First Known Use: 1661

See Words from the same year

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous

FLUID Defined for English Language Learners

fluid

play

adjective

Definition of fluid for English Language Learners

: capable of flowing freely like water
—used to describe something that can change easily or that changes often
: having or showing a smooth and easy style

fluid

noun

Definition of fluid for English Language Learners

: a substance that is able to flow freely : a liquid substance

FLUID Defined for Kids

fluid

play

adjective flu·id \ ˈflü-əd \

Definition of fluid for Students

1 :capable of flowing like a liquid or gas

fluid lava

2 :having a graceful or flowing style or appearance

a dancer's fluid movement

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fluidly

adverb

fluid

noun

Definition of fluid for Students

:something that tends to flow and take the shape of its container

Word Root of fluid

The Latin word fluere, meaning “to flow,” gives us the root flu. Words from the Latin fluere have something to do with flowing. A fluid is a substance that flows and is usually a liquid. When someone is fluent in a language the words flow out of her or him. Anything superfluous, or extra, has flowed forth beyond what is necessary.

Medical Dictionary

fluid

play

adjective flu·id \ ˈflü-əd \

medical Definition of fluid

:having particles that easily move and change their relative position without a separation of the mass and that easily yield to pressure :capable of flowing

fluid

noun

medical Definition of fluid

:a substance (as a liquid or gas) tending to flow or conform to the outline of its container; specifically :one in the body of an animal or plant — see cerebrospinal fluid, seminal fluid