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

Officials did not provide a breakdown of casualty figures. —Stephen Sorace, FOXNews.com, 30 June 2025

Despite hundreds of thousands of casualties, the Russian military can still generate forces far greater than Ukraine. —Tim Lister, CNN Money, 29 June 2025

In response to the attacks last Saturday, Iran launched a missile attack on Monday against a U.S. military base in Qatar that resulted in no damage or casualties. —Lauren Green, The Washington Examiner, 29 June 2025

Jahangir did not break down the casualty figures but said the attack had hit the prison’s infirmary, engineering building, judicial affairs and visitation hall, where visiting family members were killed and injured. —David Rising, Chicago Tribune, 29 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