cataclysm
Definitions
A large-scale and violent event in the natural world.
A sudden, violent upheaval or disaster that causes great change or destruction.
Examples
The sudden earthquake was a total cataclysm that left the entire city in ruins.
Historians often debate whether the collapse of the empire was caused by internal strife or an external cataclysm.
The environmental report warned that climate change could lead to a global cataclysm if left unchecked.
Synonyms
disaster catastrophe calamity tragedy upheaval devastation ruin