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

• 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

As Atwell sprinted to the end zone, Stafford chased after him, arms outstretched in delirium. —Adam Grosbard, Oc Register, 28 Sep. 2025

The band that once was arguably rock’s greatest is going out on a high that is still a hell of a lot closer to delirium than resignation. —Chris Willman, Variety, 20 Sep. 2025

The result is a book of willful delirium, one that deconstructs its own narrative. —Literary Hub, 4 Sep. 2025

Previous versions of this story understandably tend to dwell on the doctor’s delirium. —Bilge Ebiri, Vulture, 26 Aug. 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