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

Shah diagnosed delirium and said possible causes included anesthesia, oxygen problems and an elevated heart rate. — Sarah Rumpf-Whitten, FOXNews.com, 4 Aug. 2026

Symptoms of this condition include delirium, seizures, an abnormal heart rhythm, hyperthermia, coma and death. — Andrew Yockey, The Conversation, 24 July 2026

Using Auto-Tune as a creative tool in bolder ways than ever, its DJ-style delirium and pop radio polish were emotionally raw, aurally vibey, and all around hot. — Lina Lecaro, SPIN, 24 July 2026

The Jayhawk legend drove to the basket and missed a floater but tipped in his own miss to push the KU team over the 83-point target score and send Link Arena into delirium. — Christian Marshall, Kansas City Star, 23 July 2026

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

• agrobacterium
• corynebacterium
• mycobacterium
• bacterium
• deuterium
• imperium
• puerperium
• venereum
• 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