9 Grammatical Pitfalls


[floo-id] /ˈflu ɪd/
a substance, as a liquid or gas, that is capable of flowing and that changes its shape at a steady rate when acted upon by a force tending to change its shape.
pertaining to a substance that easily changes its shape; capable of flowing.
consisting of or pertaining to fluids.
changing readily; shifting; not fixed, stable, or rigid:
fluid movements.
convertible into cash:
fluid assets.
Origin of fluid
1595-1605; < Latin fluidus, equivalent to flu(ere) to flow + -idus -id4
Related forms
fluidal, adjective
fluidly, fluidally, adverb
fluidness, noun
nonfluid, noun
nonfluidly, adverb
unfluid, adjective
Can be confused
fluid, gas, liquid (see synonym study at liquid)
2. See liquid. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for fluid
  • Lighter fluid is a flammable liquid found in cigarette lighters and other types of lighters.
  • Windshield washer fluid is a brightly colored liquid made of methanol, a poisonous alcohol.
  • Sudden drainage of yellow or green fluid from the ear may mean a ruptured eardrum.
  • fluid builds up in the lungs and the brain swells, leading to confusion and even coma.
  • The subject is too large, and the situation too fluid for that.
  • The lower the viscosity, the more fluid the lava is.
  • Well the article described a pendant drop of fluid as the result of one experiment.
  • Even before you were born, she was exposing you to different flavors in the womb via amniotic fluid.
  • Another major sign of transmission problems is the presence of fluid leaks.
  • Hydrocephalus is a buildup of fluid inside the skull, leading to brain swelling.
British Dictionary definitions for fluid


a substance, such as a liquid or gas, that can flow, has no fixed shape, and offers little resistance to an external stress
capable of flowing and easily changing shape
of, concerned with, or using a fluid or fluids
constantly changing or apt to change
smooth in shape or movement; flowing
Derived Forms
fluidal, adjective
fluidness, noun
fluidly, fluidally, adverb
Word Origin
C15: from Latin fluidus, from fluere to flow
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for fluid

early 15c., from Middle French fluide (14c.) and directly from Latin fluidus "fluid, flowing, moist," from fluere "to flow" (see fluent). Figurative use from 1640s. Related: Fluidly.


1660s, from fluid (adj.).

Online Etymology Dictionary, © 2010 Douglas Harper
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fluid in Medicine

fluid flu·id (flōō'ĭd)
An amorphous substance whose molecules move freely past one another; a liquid or gas. adj.
Of or characteristic of a fluid.

flu·id'i·ty (-ĭd'ĭ-tē) or flu'id·ness n.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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fluid in Science
A state of matter, such as liquid or gas, in which the component particles (generally molecules) can move past one another. Fluids flow easily and conform to the shape of their containers. See also state of matter, viscosity.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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fluid in Culture

fluid definition

In physics, a substance that flows — usually a liquid or a gas.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Slang definitions & phrases for fluid


Related Terms

embalming fluid

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
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