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

• victim
• fatality

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

Watson, 46, who as deputy criminal chief was serving in one of the office’s senior positions, became another casualty in President Donald Trump’s mission to purge anyone found to have worked in some way for special counsel Jack Smith. —Jay Weaver july 14, Miami Herald, 14 July 2025

The Battle of the Somme ground on for another four months, at the cost of more than a million British, French, and German casualties. —Ed Caesar, New Yorker, 13 July 2025

The Israeli Defense Force (IDF) tactics, chosen mostly to minimize casualties among their ground troops, have by now killed over 50,000 Palestinians in Gaza. —Daniel R. Depetris, MSNBC Newsweek, 11 July 2025

June brought the highest monthly civilian casualties of the war, with 232 people killed and 1,343 wounded, the U.N. human rights mission in Ukraine said Thursday, as Russia launched 10 times more drones and missiles than the same month last year. —arkansasonline.com, 11 July 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