hal·​lu·​ci·​no·​sis hə-ˌlü-sə-ˈnō-səs How to pronounce hallucinosis (audio)
: a pathological mental state characterized by hallucinations

Example Sentences

Recent Examples on the Web Boes was working with a patient who had a rare disorder called peduncular hallucinosis, in which damage to the thalamus, a structure at the center of the brain, causes visual hallucinations. Grace Huckins, Wired, 17 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hallucinosis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


New Latin

First Known Use

1905, in the meaning defined above

Time Traveler
The first known use of hallucinosis was in 1905

Dictionary Entries Near hallucinosis

Cite this Entry

“Hallucinosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hallucinosis. Accessed 21 Mar. 2023.

Medical Definition


hal·​lu·​ci·​no·​sis hə-ˌlüs-ᵊn-ˈō-səs How to pronounce hallucinosis (audio)
plural hallucinoses -ˌsēz How to pronounce hallucinosis (audio)
: a pathological mental state characterized by hallucinations

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