hallucinate
Americanverb (used without object)
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hallucinates,
present (3rd person singular)
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hallucinated,
past participle, past
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hallucinating
present participle
-
to see or hear things that do not exist outside the mind; have hallucinations.
People who ingested this fungus often hallucinated, seeing colored lights or hearing voices.
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Computers, Digital Technology. (of a machine learning program) to produce false information contrary to the intent of the user and present it as if true and factual.
verb (used with object)
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hallucinates,
present (3rd person singular)
-
hallucinated,
past participle, past
-
hallucinating
present participle
-
to see or hear (things that do not exist outside the mind); have hallucinations about.
In dramatic moments, the character hallucinates a very funny animated bear.
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Archaic. to affect with hallucinations.
verb
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
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hallucinatesimple
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hallucinatessimple
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have hallucinatedperfect
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has hallucinatedperfect
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am hallucinatingprogressive
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are hallucinatingprogressive
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is hallucinatingprogressive
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have been hallucinatingperfect progressive
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has been hallucinatingperfect progressive
Past
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hallucinatedsimple
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had hallucinatedperfect
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was hallucinatingprogressive
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were hallucinatingprogressive
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had been hallucinatingperfect progressive
Future
Etymology
Origin of hallucinate
First recorded in 1595–1605; from Latin hallūcinātus “wandered mentally” past participle of hallūcinārī, variant of (h)ālūcinārī “to dream, talk idly, wander mentally”
Explanation
To hallucinate is to see or hear something that's not really there. If you hallucinate, it's a bit like dreaming while being awake. When someone hallucinates, what they're perceiving seems very real and vivid, although it's not. Many different things can cause a person to hallucinate, including drugs, mental illness, damage to the brain, and even lack of adequate sleep. Some people hallucinate regularly, if mildly, just as they're falling asleep at night. The original meaning of hallucinate was "deceive," from the Latin hallucinatus, "wander in the mind."
Vocabulary lists containing hallucinate
The Marvels
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Ungifted
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The Legend of Auntie Po
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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:
But new research suggests there may be a more concerning issue emerging: humans can begin to "hallucinate with AI."
From Science Daily ● May 11, 2026
As they do, however, experts have warned their potential to make things up - or "hallucinate" as the industry describes it - could intensify.
From BBC ● Apr. 30, 2026
By their nature, AI models hallucinate and generate inconsistent answers—so why are they suddenly useful enough to get real work done?
From The Wall Street Journal ● Apr. 19, 2026
AI tools are known to hallucinate, or make up information.
From Los Angeles Times ● Apr. 14, 2026
Perhaps it had escaped and was hiding in one of the dark corners of the room, or maybe Joseph’s fever was causing him to hallucinate.
From "The Marvels" by Brian Selznick
The fact that no one made it, that it’s the creation of a machine that hallucinates in exchange for electricity, only intensifies the sick, empty feeling the track leaves behind.
From Salon ● Aug. 6, 2026
It explains why AI hallucinates and makes other mistakes.
From The Wall Street Journal ● Feb. 26, 2026
"This means that visual information about things happening in the outside world becomes less accessible to our consciousness. To fill this gap in the puzzle, our brain inserts fragments from memory -- it hallucinates."
From Science Daily ● Feb. 15, 2026
What good is AI that analyzes financial data if it hallucinates numbers?
From MarketWatch ● Nov. 3, 2025
Sometimes Enrique hallucinates that someone is chasing him.
From "Enrique's Journey" by Sonia Nazario
There have been a smattering of cases that hint at possible outcomes, like the 2024 case involving an Air Canada chatbot that hallucinated that a discount was available for bereavement tickets.
From The Wall Street Journal ● Sep. 22, 2026
What about making real that hallucinated series with Cillian Murphy?
From Los Angeles Times ● Jun. 9, 2026
"Many of these manipulated images have the hallmarks of imperfect AI-generation: odd angles, blurred details, and hallucinated features that don't align with reality," Africk told AFP.
From Barron's ● Mar. 9, 2026
Earlier this year, Apple suspended its Apple Intelligence news summary tool in the UK after it hallucinated false headlines and presented them as real news.
From BBC ● Mar. 20, 2025
It was as if she were afraid she had hallucinated him and needed proof to the contrary.
From "Sula" by Toni Morrison
"This risk of a model making errors or hallucinating cannot be fully avoided in any technical way," said Munich Re's head of AI insurance, Michael von Gablenz.
From Barron's ● Mar. 15, 2026
Participants in the second schizophrenia group, those without recent hallucinations, showed brain responses that fell between the healthy group and the hallucinating group.
From Science Daily ● Jan. 23, 2026
I have yet to see any implementation of A.I. that I could consider either general-purpose or foundational, and I think it’s absurd to look at the hallucinating chatbots and inaccurate A.I.
From Slate ● Nov. 22, 2025
To prevent such AI from hallucinating, "you need to make sure it's penalised in its training, if it gives you something that doesn't exist," says Prof MacMahon.
From BBC ● Feb. 27, 2025
When he returned, he was boiling up with a fever and hallucinating.
From "The Gene" by Siddhartha Mukherjee
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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
