<p><strong>Noun</strong></p><ul><li>plural casualties.</li><li>Military: a member of the armed forces lost to service through death, wounds, sickness, capture, or because their whereabouts or condition cannot be determined.</li><li>casualties: loss in numerical strength through any cause, as death, wounds, sickness, capture, or desertion.</li><li>one who is injured or killed in an accident: There were no casualties in the traffic accident.</li><li>any person, group, thing, etc., that is harmed or destroyed as a result of some act or event: Their house was a casualty of the fire.</li><li>a serious accident, especially one involving bodily injury or death.</li></ul>