hallucinate
Americanverb (used without object)
-
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.
People who ingested this fungus often hallucinated, seeing colored lights or hearing voices.
-
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)
-
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.
-
Archaic. to affect with hallucinations.
verb
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
-
hallucinatesimple
-
hallucinatessimple
-
have hallucinatedperfect
-
has hallucinatedperfect
-
am hallucinatingprogressive
-
are hallucinatingprogressive
-
is hallucinatingprogressive
-
have been hallucinatingperfect progressive
-
has been hallucinatingperfect progressive
Past
-
hallucinatedsimple
-
had hallucinatedperfect
-
was hallucinatingprogressive
-
were hallucinatingprogressive
-
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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Ungifted
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The Legend of Auntie Po
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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 some users find that much like the models they’re built on—which can hallucinate, misinterpret or even commit spontaneous acts of cybercrime—their assistants, too, can behave unpredictably.
From The Wall Street Journal ● Oct. 8, 2026
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
AI tools are known to hallucinate, or make up information.
From Los Angeles Times ● Apr. 14, 2026
My fever gets worse, and during one terrible evening I start to hallucinate.
From "Landscape with Invisible Hand" by M.T. Anderson
Google said Gemini hallucinates less than other models and that it is working to improve it.
From The Wall Street Journal ● Apr. 14, 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
Last year, a Los Angeles attorney was fined for submitting a filing full of legal citations that were hallucinated by ChatGPT.
From Los Angeles Times ● Mar. 18, 2026
It hallucinated that my actual finish was the same as the target finish time it originally predicted.
From The Wall Street Journal ● Nov. 3, 2025
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
Meghan Cliffel was eight months postpartum from the birth of her second daughter when she began hallucinating.
From BBC ● Aug. 19, 2026
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
A hallucinating encyclopedia may not be exactly what you’re looking for when you’re doing research, but that’s what writer Stephen Harrison found when he dug into Elon Musk’s new A.I.-powered Grokipedia.
From Slate ● Nov. 17, 2025
I do not tell her about hallucinating Will.
From "Insurgent" by Veronica Roth
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions 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.
