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 of casualty

• 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

In a social media post, authorities said the drones caused material damage, but no casualties. —Npr Staff, NPR, 24 Apr. 2026

Through a detailed examination of footage posted by Israeli soldiers themselves, the film documents potential war crimes, including civilian casualties, torture, and destruction of infrastructure, delivering unprecedented accountability and real-time evidence. —Patrick Hipes, Deadline, 23 Apr. 2026

Hezbollah fighters have also inflicted significant casualties on invading Israeli forces. —David Brennan, ABC News, 23 Apr. 2026

At this point, majorities of Americans say the war with Iran is not worth it when asked about the financial cost, the increase in the price of gasoline, regime change in Iran and the number of casualties. —Steve Liesman, CNBC, 23 Apr. 2026

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