0 causing a lot of destruction, or a sudden, violent change: --
The consequences of bankruptcy are potentially cataclysmic.
Saturn’s rings weren't formed by a single cataclysmic event.
Greenhouse gases could cause a cataclysmic change in the world's climate.
The Depression was a worldwide cataclysmic event.
Some events may have small consequences, while others are nearly cataclysmic in their impact.