illusion
Americannoun
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illusions
plural
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something that deceives by producing a false or misleading impression of reality.
- Synonyms:
- chimera, fantasy, aberration
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the state or condition of being deceived; misapprehension.
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an instance of being deceived.
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Psychology. a perception, as of visual stimuli optical illusion, that represents what is perceived in a way different from the way it is in reality.
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a very thin, delicate tulle of silk or nylon having a cobwebbed appearance, for trimmings, veilings, and the like.
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Obsolete. the act of deceiving; deception; delusion.
noun
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a false appearance or deceptive impression of reality
the mirror gives an illusion of depth
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a false or misleading perception or belief; delusion
he has the illusion that he is really clever
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psychol a perception that is not true to reality, having been altered subjectively in some way in the mind of the perceiver See also hallucination
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a very fine gauze or tulle used for trimmings, veils, etc
Synonym Usage
illusion, hallucination, delusion refer to false perceptions or ideas. An illusion is a false mental image produced by misinterpretation of things that actually exist: A mirage is an illusion produced by reflection of light against the sky. A hallucination is a perception of a thing or quality that has no physical counterpart: Under the influence of LSD, Terry had hallucinations that the living-room floor was rippling. A delusion is a persistent false belief: A paranoiac has delusions of persecution.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of illusion
First recorded in 1300–50; Middle English from Latin illūsiōn- (stem of illūsiō ) “irony, mocking,” equivalent to illūs(us), past participle of illūdere “to mock, ridicule” ( il- il- 1 + lūd- play ( see ludicrous) + -tus past participle suffix) + -iōn- -ion
Explanation
An illusion is something that isn't real. It may look real, but it's actually fake — just a crafty construction or fantasy. Like the old rabbit-out-of-the-hat trick practiced by magicians around the globe. An illusion is an act of deception. Some optical illusions are pretty cool to watch, but an illusion can also point to an erroneous belief or false perception of reality, which is where you start getting into hallucination territory — seeing things that aren't there. You can give the illusion that you’re fascinated by your professor’s lecture by chewing on your pencil, furrowing your brow, and making sure to nod enthusiastically every so often.
Vocabulary lists containing illusion
"The Crucible" -- Vocabulary from all 4 Acts
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English Words Derived from French, List 1
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Smoke and Mirrors: The Lingo of Illusion and Deception
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Mathias J. Weber and Russell E. Vanderhoff’s seductively streamlined Health-o-Meter scale gave the illusion that homeowners could be scientists, for the first time monitoring their own weight and growth.
From Los Angeles Times ● Oct. 7, 2026
This creates the irresistible illusion that dogs think like us.
From The Wall Street Journal ● Oct. 5, 2026
The runway slope and width create what’s known as a crowned runway illusion that distorts a pilot’s perception of height and distance during their final approach.
From Los Angeles Times ● Oct. 3, 2026
Just make sure their success isn’t an illusion.
From The Wall Street Journal ● Sep. 25, 2026
The sensory details of the illusion are so luscious, it is almost dizzying.
From "The Night Circus" by Erin Morgenstern
Parton, who died Tuesday at age 80, made a career out of building illusions she delighted in dismantling.
From Los Angeles Times ● Aug. 26, 2026
As critical as he is of his own government, he has few illusions about the West.
From BBC ● Aug. 13, 2026
Brown, a veteran quantitative trader, covers a huge range of statistical illusions, delusions, distortions, and disinformation—in fields ranging from public health to foreign policy, from portfolio management to crime novels.
From The Wall Street Journal ● Jul. 14, 2026
"He would never do that, let's not have any illusions," said Tikhanovskaya, who recently returned from a trip to Kyiv.
From Barron's ● Jun. 26, 2026
"How does it feel to be free of one's illusions?"
From "Invisible Man" by Ralph Ellison
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
