Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A continuous, amorphous substance whose molecules move freely past one another and that has the tendency to assume the shape of its container; a liquid or gas.
  • adjective Of, relating to, or characteristic of a fluid.
  • adjective Readily reshaped; pliable.
  • adjective Smooth and flowing; graceful.
  • adjective Changing or tending to change; variable.
  • adjective Characterized by or allowing social mobility.
  • adjective Convertible into cash.

from The Century Dictionary.

  • Capable of flowing; liquid or gaseous; consisting of a substance incapable of resisting forces (tangential stresses) tending to change its shape.
  • Not fixed or rigid; flowing; shifting; fluent.
  • noun A substance which flows or is capable of flowing; a substance which is incapable of resisting forces (tangential stresses) tending to change its shape without altering its size.
  • noun Some hypothetical supersensible substance conceived as analogous to known fluids. See fluidism.
  • noun See the adjectives.
  • noun See the adjectives.

from the GNU version of the Collaborative International Dictionary of English.

  • noun A fluid substance; a body whose particles move easily among themselves.
  • noun a measure of capacity equal to one eighth of a fluid ounce.
  • noun In England, a measure of capacity equal to the twentieth part of an imperial pint. For water, this is the weight of the avoirdupois ounce, or 437.5 grains.
  • noun (Physiol.) The circulating blood and lymph, the chyle, the gastric, pancreatic, and intestinal juices, the saliva, bile, urine, aqueous humor, and muscle serum are the more important fluids of the body. The tissues themselves contain a large amount of combined water, so much, that an entire human body dried in vacuo with a very moderate degree of heat gives about 66 per cent of water.
  • noun See under Burning, Elastic, etc.
  • adjective Having particles which easily move and change their relative position without a separation of the mass, and which easily yield to pressure; capable of flowing; liquid or gaseous.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun physics 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
  • adjective not comparable Of, or relating to fluid.
  • adjective In a state of flux; subject to change.
  • adjective Moving smoothly, or giving the impression of a liquid in motion.
  • adjective of an asset Convertible into cash.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective in cash or easily convertible to cash
  • noun a substance that is fluid at room temperature and pressure
  • noun continuous amorphous matter that tends to flow and to conform to the outline of its container: a liquid or a gas
  • adjective subject to change; variable
  • adjective affording change (especially in social status)
  • adjective characteristic of a fluid; capable of flowing and easily changing shape
  • adjective smooth and unconstrained in movement

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[From Middle English, flowing, from Old French fluide, from Latin fluidus, from fluere, to flow; see bhleu- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin fluidus ("flowing, fluid"), from fluere ("to flow"), akin to Ancient Greek φλύειν (fluein, "to swell, overflow"). Several related terms in English from Latin (fluent, flux), and cognate from Proto-Indo-European (via Germanic) with flow.

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Examples

  • Around each joint has grown up a strong sheath of tough, fibrous tissue to hold the bones together; and, inside this, between the heads of the bones, is a very delicate little bag, or pouch, containing a few drops of smooth, slippery fluid (_synovial fluid_) to lubricate the movements of the joint.

    A Handbook of Health Woods Hutchinson 1896

  • As the layers become continuous with each other at different points, the arachnoid, like the pericardium, forms a shut sac, and, like other serous membranes, it secretes a fluid, known as the _arachnoid fluid_.

    The People's Common Sense Medical Adviser in Plain English or, Medicine Simplified, 54th ed., One Million, Six Hundred and Fifty Thousand Ray Vaughn Pierce 1877

  • Moving over matter which has the qualities that we denote by the term fluid, the swayings which the air produces are of a peculiar sort, though they much resemble those of the fiddle string.

    Outlines of the Earth's History A Popular Study in Physiography Nathaniel Southgate Shaler 1873

  • Does anyone know if the smell of the fluid is an issue?

    Do guys like zippos. they are my tops for the most reliable piece of gear. never go to deer camp without it. 2010

  • Does anyone know if the smell of the fluid is an issue?

    Do guys like zippos. they are my tops for the most reliable piece of gear. never go to deer camp without it. 2010

  • These are usually considered low risk procedures, but the risk depends on where the fluid is and how sick your child is at the time.

    Fluid Aspiration and Drainage (Parcentesis/Thoracentesis) 2010

  • If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe.

    Balkinization 2007

  • If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe.

    Balkinization 2007

  • If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe.

    Balkinization 2007

  • If a large amount of fluid is present, abnormal cells may be detected by cytology if this fluid is aspirated with a syringe.

    Balkinization 2007

  • A potential answer lies in the work of the British psychologist Raymond Cattell, who in the early 1940s introduced the concepts of fluid and crystallized intelligence. Cattell defined fluid intelligence as the ability to reason, analyze, and solve novel problems—what we commonly think of as raw intellectual horsepower. Innovators typically have an abundance of fluid intelligence. It is highest relatively early in adulthood and diminishes starting in one’s 30s and 40s. This is why tech entrepreneurs, for instance, do so well so early, and why older people have a much harder time innovating.Crystallized intelligence, in contrast, is the ability to use knowledge gained in the past. Think of it as possessing a vast library and understanding how to use it. It is the essence of wisdom. Because crystallized intelligence relies on an accumulating stock of knowledge, it tends to increase through one’s 40s, and does not diminish until very late in life.Careers that rely primarily on fluid intelligence tend to peak early, while those that use more crystallized intelligence peak later. For example, Dean Keith Simonton has found that poets—highly fluid in their creativity—tend to have produced half their lifetime creative output by age 40 or so. Historians—who rely on a crystallized stock of knowledge—don’t reach this milestone until about 60.

    Your Professional Decline Is Coming (Much) Sooner Than You Think Arthur C. Brooks 2022

Comments

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  • Add to this everything that rhymes with fluid: druid, pluid, fruid, squid.

    September 7, 2010

  • There once was a venturesome druid

    who craved a dominion more fluid

    than forest or lea,

    so he jumped in the sea

    and was eaten alive by a squid.

    September 7, 2010

  • Oh, man! You made me laugh so hard that ink came out of my nose.

    September 7, 2010