Accident, casualty and mishap are synonyms when they designate chance or a chance event bringing injury or loss.
Accident is broadest in its application, being used of events that involve persons or things, or injuries or losses, serious or slight.
- he was crippled by the accident
- a railway accident
- owing to an accident to the machines one department was closed down
Casualty commonly implies destruction, especially of life, and is chiefly applied to an individual whose death, serious injury, or even desertion constitutes a loss to a military (or similar) force engaged in hazardous activities.
- the regiment suffered heavy casualties
As applied to insurance accident and casualty are usually distinguished: accident insurance is a provision against injury to oneself through accident; casualty insurance is a provision for indemnification for loss from accident (as fire or burglary) and especially for damages incurred through one’s liability for injury or loss to others.
Mishap as a rule is applied only to slight accidents, especially those involving disappointment or frustration.
- a day seldom passes without one mishap or another