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

The casualties included six people who were in serious condition and three who were in mild condition, the MDA said. —Becca Longmire, PEOPLE, 8 Sep. 2025

The biggest casualty, says Srivastava, will be the goodwill between India and the United States, built after decades of bitterness over Washington's support of India's adversaries like Pakistan. —Omkar Khandekar, NPR, 8 Sep. 2025

In all, it is estimated that total casualties from the D-Day push topped half-a-million. —Jim Clash, Forbes.com, 8 Sep. 2025

Debris from one Russian drone fell on the territory of the Ilsky Oil Refinery in the Krasnodar region, local officials said, causing a fire at one of the technological installations which was quickly extinguished with no casualties. —David Brennan, ABC News, 7 Sep. 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