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
AI systems can "hallucinate", inventing plausible but incorrect answers.
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
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
The puppeteer even hallucinates seeing Eric standing next to him, wisecracking and poking holes in his ego - because "puppets say the things we can't".
From BBC ● May 26, 2024
Sometimes Enrique hallucinates that someone is chasing him.
From "Enrique's Journey" by Sonia Nazario
What about making real that hallucinated series with Cillian Murphy?
From Los Angeles Times ● Jun. 9, 2026
It hallucinated citations and got facts wrong, and you risked looking like a fool in front of a professor for trusting it.
From The Wall Street Journal ● May 26, 2026
One out of every five answers "contained major accuracy issues, including hallucinated details and outdated information."
From Barron's ● Oct. 21, 2025
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
When generative AI systems give incorrect answers, people often describe the problem as AI "hallucinating at us," meaning the technology produces false information that users may mistakenly believe.
From Science Daily ● May 11, 2026
"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
"I had to call my sisters to say, 'Did I hear this right or am I hallucinating?'"
From BBC ● Dec. 13, 2025
So if we’re hallucinating, we may not be hallucinating exactly the same thing.
From Salon ● Nov. 16, 2024
But I think I must have been hallucinating or something, because I’ve had conversations with God since then and He’s like, Nope, don’t know what you’re talking about, Benny.
From "The Book of Unknown Americans" by Cristina Henríquez
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.
