hallucinate
Americanverb (used without object)
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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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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
- hallucinator noun
- nonhallucinated adjective
- unhallucinated adjective
- unhallucinating adjective
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”
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.
AI agents are increasingly widespread but experts warn they can "hallucinate" non-existent events.
From Barron's • Feb. 27, 2026
As is well-known, AI can screw up even the simplest facts, or just hallucinate and invent details, so it pays to check everything.
From The Wall Street Journal • Feb. 24, 2026
What we don’t know yet is when they hallucinate, or when they veer from guidelines or recommendations.
From Slate • Jan. 21, 2026
“They hallucinate and have trouble with reasoning,” he said.
From MarketWatch • Nov. 29, 2025
My fever gets worse, and during one terrible evening I start to hallucinate.
From "Landscape with Invisible Hand" by M.T. Anderson
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.
