hallucinate

verb

hal·​lu·​ci·​nate hə-ˈlü-sə-ˌnāt 

hallucinated; hallucinating

transitive verb

1

: to affect with visions or imaginary perceptions

2

: to perceive or experience as a hallucination

intransitive verb

: to have hallucinations

hallucinator

hə-ˈlü-sə-ˌnā-tər 

noun

Examples of hallucinate in a Sentence

The patient may hallucinate if she has a fever.

Recent Examples on the Web

The report was riddled with fake citations that appeared to be hallucinated by AI, which the White House attributed to formatting errors; HHS then corrected the report by removing the false citations and swapping in new references. —Matteo Wong, The Atlantic, 13 Feb. 2026

Models will always be capable of hallucinating, so the objective is to build full systems that ensure—though not zero risk—but reliability superior to current processes. —Sylvain Duranton, Forbes.com, 30 Jan. 2026

The weather was accurate but the towns were hallucinated by the computer program. —Krista Kafer, Denver Post, 25 Jan. 2026

What if a person was hallucinating, and a voice told them to commit the crime? —Literary Hub, 20 Jan. 2026

Word History

Etymology

Latin hallucinatus, past participle of hallucinari, allucinari to prate, dream, modification of Greek alyein to be distressed, to wander

First Known Use

circa 1834, in the meaning defined at transitive sense 1

Kids Definition

hallucinate

verb

hal·​lu·​ci·​nate hə-ˈlüs-ə-ˌnāt 

hallucinated; hallucinating

: to have hallucinations or experience as a hallucination

Medical Definition

hallucinate

verb

hal·​lu·​ci·​nate hə-ˈlüs-ᵊn-ˌāt 

hallucinated; hallucinating

transitive verb

1

: to affect with visions or imaginary perceptions

the patient is not hallucinated

2

: to perceive or experience as a hallucination

may hallucinate monsters or attackers

—M. J. Horowitz

intransitive verb

: to have hallucinations