de·​lir·​i·​um di-ˈlir-ē-əm How to pronounce delirium (audio)
: an acute (see acute sense 1a(2)) mental disturbance characterized by confused thinking and disrupted attention usually accompanied by disordered speech and hallucinations
: frenzied excitement
he would stride about his room in a delirium of joyThomas Wolfe
a crowd in a state of delirium

Example Sentences

In her delirium, nothing she said made any sense. shoppers running around in a delirium the day before Christmas
Recent Examples on the Web Matt Damon and Casey Affleck movie Gerry, from 2002, about two men who go off-trail during a desert hike, lose their way, and suffer from delirium until one of them is killed by the other. K. Austin Collins, Rolling Stone, 9 Feb. 2023 Some days the ills of the city seem miasmal and mental, a delirium of drugs and dysfunctions, a souring in the gut like dysentery. Andrew Cockburn, Harper’s Magazine , 5 Jan. 2023 From here, symptoms can become progressively more severe, expanding to include jaundice, pancreatic inflammation, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, and multi-organ dysfunction. Erin Prater, Fortune Well, 16 Feb. 2023 Users experienced delirium, psychosis and sometimes even fell into a coma. Gabe Allen, Discover Magazine, 1 Feb. 2022 Barry is an exuberant anarchist who traffics in polystylistic delirium. Alex Ross, The New Yorker, 9 Aug. 2021 At that point, the crowd already had been sent into delirium, witnessing the first rally from a three-goal deficit in the third period in the NHL this season and the first for the Stars since 2015-16. Schuyler Dixon, Chicago Tribune, 24 Nov. 2022 Yordan Alvarez became the first player in playoff history to hit a two-out, walk-off home run with his club trailing by multiple runs, a wallop off Robbie Ray capping an industrious comeback and sending Minute Maid Park into delirium. Gabe Lacques, USA TODAY, 12 Oct. 2022 There were hours that disappeared into delirium and slow, clear agonizing minutes. Joshuah Bearman, Vulture, 25 Aug. 2021 See More

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

Word History


Latin, from delirare to be crazy, literally, to leave the furrow (in plowing), from de- + lira furrow — more at learn

First Known Use

circa 1563, in the meaning defined at sense 1

Time Traveler
The first known use of delirium was circa 1563

Dictionary Entries Near delirium

Cite this Entry

“Delirium.” Dictionary, Merriam-Webster, Accessed 22 Mar. 2023.

Kids Definition


de·​lir·​i·​um di-ˈlir-ē-əm How to pronounce delirium (audio)
: a mental disturbance marked by confusion, disturbed speech, and hallucinations
: wild excitement

Medical Definition


de·​lir·​i·​um di-ˈlir-ē-əm How to pronounce delirium (audio)
: a mental disturbance characterized by confusion, disordered speech, and hallucinations

More from Merriam-Webster on delirium

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