n. Chance, or what happens by chance; accident; contingency.n. An unfortunate chance or accident, especially one resulting in bodily injury or death; specifically, disability or loss of life in battle or military service from wounds, etc.: as, the casualties were very numerous.n. In Scots law, an emolument due from a vassal to his superior, beyond the stated yearly duties, upon certain casual events.n. plural In the military service, the losses in a command due to any cause whatsoever, as resignation, discharge, dismissal, desertion, capture, wounds, or death.