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

Content must be authentic and showcase real expertise, not hallucinated knowledge. —Joe Toscano, Forbes.com, 3 Sep. 2025

One health-care AI model confidently hallucinated a nonexistent body part. —Craig Spencer, The Atlantic, 29 Aug. 2025

Regardless, the guides require reading comprehension skills and don’t offer random, hallucinated, or uncited thoughts about the text. —Joelle Renstrom august 28, Literary Hub, 28 Aug. 2025

Zane Wach, 14, hallucinated and walked off a cliff while climbing Mount Whitney in Northern California on June 10. —Abigail Adams, People.com, 18 Aug. 2025

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