- the former theory that geologic changes are caused in general by sudden upheavals rather than gradually
- an outlook envisioning imminent catastrophe
- a. The doctrine that major changes in the earth's crust result from sudden catastrophes, such as the impact of a large meteor, rather than from gradual evolutionary processes.b. The doctrine that changes in the earth's fauna and flora result from major catastrophic events that cause the die-off of many organisms and are followed by the appearance of new types of organisms.
- The prediction or expectation of cataclysmic upheaval, as in political or social developments.
- (geology) The doctrine that sudden catastrophes, rather than continuous change, cause the main features of the Earth's crust