casualty

noun

ca·​su·​al·​ty ˈka-zhəl-tē 

ˈkazh-wəl-,

ˈka-zhə-wəl- 

plural casualties

1

a

: a military person lost through death, wounds, injury, sickness, internment, or capture or through being missing in action

The army sustained heavy casualties.

b

: a person or thing injured, lost, or destroyed : victim

the ex-senator was a casualty of the last election

2

: serious or fatal accident : disaster

losses from fire, storm, or other casualty

—J. S. Seidman

3

archaic : chance, fortune

losses that befall them by mere casualty

—Sir Walter Raleigh

Synonyms

• fatality
• loss
• prey
• victim

Examples of casualty in a Sentence

a low number of casualties

the real casualties in the war against drugs are millions of innocent children

Recent Examples on the Web

Israeli leaders say the system isn’t 100% guaranteed, but credit it with preventing serious damage and countless casualties. —Christopher Bodeen, Chicago Tribune, 21 June 2025

But the conflict has only escalated, with Russia’s launching some of its most extensive strikes in a war that has claimed hundreds of thousands of casualties, and Ukraine’s carrying out the audacious Operation Spiderweb drone attack, which damaged or destroyed strategic aircraft inside Russia. —Adam Rasmi, Time, 20 June 2025

Iran has not been offering regular death tolls during the conflict and has minimized casualties in the past. —Nbc News, NBC news, 20 June 2025

Iran has fired barrages of missiles at Israel, dozens of which have breached Israel's multi-layered defense system, causing damage to infrastructure and civilian casualties. —Amira El-Fekki‎, MSNBC Newsweek, 19 June 2025

Word History

Etymology

see casual entry 1

First Known Use

15th century, in the meaning defined at sense 3

Kids Definition

casualty

noun

ca·​su·​al·​ty ˈkazh-əl-tē 

ˈkazh-(ə-)wəl-

plural casualties

1

: a serious or fatal accident : disaster

2

a

: a military person lost (as by death or capture) during warfare

b

: a person or thing injured, lost, or destroyed

Medical Definition

casualty

noun

ca·​su·​al·​ty ˈkazh-əl-tē, ˈkazh-(ə-)wəl- 

plural casualties

1

: a serious or fatal accident

2

: a military person lost through death, wounds, injury, sickness, internment, or capture or through being missing in action

3

a

: injury or death from accident

b

: one injured or killed (as by accident)

Legal Definition

casualty

noun

ca·​su·​al·​ty ˈka-zhəl-tē, ˈka-zhə-wəl- 

plural casualties

1

: an unfortunate occurrence

especially : a serious and often disastrous accident

conversion of property…arising from fire, storm, shipwreck, or other casualty

—Internal Revenue Code

2

: something lost, stolen, damaged, or destroyed see also casualty gain at gain, casualty loss at loss