de·​lir·​i·​um | \ di-ˈlir-ē-əm How to pronounce delirium (audio) \

Definition of delirium

1 : an acute (see acute sense 1a(2)) mental disturbance characterized by confused thinking and disrupted attention usually accompanied by disordered speech and hallucinations
2 : frenzied excitement he would stride about his room in a delirium of joy— Thomas Wolfe a crowd in a state of delirium

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Examples of delirium in a Sentence

In her delirium, nothing she said made any sense. shoppers running around in a delirium the day before Christmas
Recent Examples on the Web In older adults, delirium is associated with a heightened risk of losing independence, developing dementia and dying. Judith Graham, CNN, "Senior Covid-19 patients suffer 'brain fog' in drawn-out recovery," 20 Oct. 2020 But the Colorado Society of Anesthesiologists warned last week against the use strong sedatives for agitation and questioned whether excited delirium exists. Patty Nieberg, Star Tribune, "Colorado city bans ketamine use amid Elijah McClain probe," 15 Sep. 2020 Previously:'Excited delirium' cited as factor in many fatal police restraint cases. Gary Craig, USA TODAY, "Will police be charged in Daniel Prude's death? This evidence may be the deciding factor," 7 Sep. 2020 If left untreated with antibiotics, the patient begins to show signs of meningoencephalitis (infection of the brain)—sensitivity to light, seizures, and delirium, for instance—before slipping into a coma and, often, dying. Jennifer Ouellette, Ars Technica, "How the Warsaw Ghetto beat back typhus during World War II," 13 Sep. 2020 Some cognitive symptoms, like brain fog and delirium, might be harder to pick up in patients who are sedated and on ventilators. Apoorva Mandavilli, New York Times, "How the Coronavirus Attacks the Brain," 9 Sep. 2020 Steroid drugs can also cause unwanted side effects, such as delirium or high blood sugar levels. Ben Guarino, Anchorage Daily News, "Cheap, widely available steroids can save lives of patients with severe COVID-19, clinical trials show," 2 Sep. 2020 These findings may explain why 40 to 60 percent of hospitalized COVID-19 patients experience psychiatric and neurological symptoms, including brain fog, delirium, crippling headaches, anxiety, and depression. TheWeek, "The COVID 'long-haulers'," 20 Sep. 2020 Boulter said officers also receive training on handcuffing, including methods to gain compliance, reasonable care, prevention of positional asphyxia, and recognition and treatment of excited delirium. Steve Smith,, "Simsbury selectmen hear update on police policies," 18 Sep. 2020

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.

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First Known Use of delirium

circa 1563, in the meaning defined at sense 1

History and Etymology for delirium

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

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Time Traveler for delirium

Time Traveler

The first known use of delirium was circa 1563

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Statistics for delirium

Last Updated

25 Oct 2020

Cite this Entry

“Delirium.” Dictionary, Merriam-Webster, Accessed 27 Oct. 2020.

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More Definitions for delirium


How to pronounce delirium (audio)

English Language Learners Definition of delirium

: a mental state in which you are confused and not able to think or speak clearly usually because of fever or some other illness
: a state of wild excitement and great happiness


de·​lir·​i·​um | \ di-ˈlir-ē-əm How to pronounce delirium (audio) \

Kids Definition of delirium

1 : a condition of mind in which thought and speech are confused usually because of a high fever or other illness
2 : wild excitement


de·​lir·​i·​um | \ di-ˈlir-ē-əm How to pronounce delirium (audio) \

Medical Definition of delirium

: a mental disturbance characterized by confusion, disordered speech, and hallucinations

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