kəˈtastrəˌfizəm noun
( -s )
1.
a. : the doctrine that changes in the earth's crust have in the past been brought about suddenly by physical forces operating in ways that cannot be observed today — compare uniformitarianism
b. : a similar doctrine concerning the changes in the earth's fauna and flora
2. : the theory that the millennium or a particular historical condition will be ushered in by a catastrophic event