delirium

noun

de·​lir·​i·​um di-ˈlir-ē-əm 

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

Synonyms of delirium

• frenzy
• rampage

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

Some passages read like dreams, others like delirium. —Amir Ahmadi Arian, The Dial, 15 Jan. 2026

There’ve been too many defiant and delirium-provoking moments not to see it that way. —Michael Silver, New York Times, 13 Jan. 2026

Patients at home are more mobile, less prone to delirium and infection, and often begin rehabilitation faster. —Lee Fleisher, STAT, 6 Jan. 2026

The Lodge takes its time building a tense atmosphere of suspense and delirium set in a remote winter cabin just days before Christmas. —Huntley Woods, Entertainment Weekly, 19 Dec. 2025

Word History

Etymology

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

Phrases Containing delirium

• delirium tremens

Rhymes for delirium

• bacterium
• deuterium
• imperium
• puerperium
• venereum
• agrobacterium
• corynebacterium
• mycobacterium
• cyanobacterium
• magisterium
• ministerium

Kids Definition

delirium

noun

de·​lir·​i·​um di-ˈlir-ē-əm 

1

: a mental disturbance marked by confusion, disturbed speech, and hallucinations

2

: wild excitement

Medical Definition

delirium

noun

de·​lir·​i·​um di-ˈlir-ē-əm 

: an acute (see acute sense 2b(1)) mental disturbance characterized by confused thinking and disrupted attention usually accompanied by disordered speech and hallucinations