abnormally dangerous activity

noun

ab·​nor·​mal·​ly dan·​ger·​ous ac·​tiv·​i·​ty

: an activity especially that is not common in or appropriate to an area, that creates a high degree of risk of harm to someone or something despite the exercise of due care, and whose value to the community in the area is outweighed by the risk of harm compare ultrahazardous activity

Note: Abnormally dangerous activities are subject to strict liability. Abnormally dangerous activity and ultrahazardous activity are sometimes used interchangeably.