Definitions
1.NounSomething that happens by chance, especially an unfortunate event; an accident, a disaster.
2.NounA person suffering from injuries or who has been killed due to an accident or through an act of violence.
3.NounSpecifically, a person who has been killed (not only injured) due to an accident or through an act of violence; a fatality.
4.NounA person in military service who becomes unavailable for duty, for any reason (notably death, injury, illness, capture, or desertion).
5.NounClipping of casualty department: the accident and emergency department of a hospital providing immediate treatment.
6.NounAn incidental charge or payment.
7.NounSomeone or something adversely affected by a decision, event or situation.
8.NounChance nature; randomness.
9.Noun↑ Douglas Harper (2001–2026), “casualty”, in Online Etymology Dictionary.