Casual

Irregular, occasional, or accidental; happening without being planned or foreseen.

The term is used to describe an event that is unanticipated or unusual. A casual sale is one that is not customary, or done in the usual course of business—such as a jeweler occasionally selling vacuum cleaners.

Casual employment is irregular, periodic, or seasonal employment, such as someone selling ice cream only during the summer. WORKERS' COMPENSATION laws in many states do not apply to casual employment.