1. relating to or involving a sudden violent change or disaster; catastrophic
Usage: formal

Examples

• The earthquake caused cataclysmal damage to the entire region.
• Climate scientists warn of cataclysmal changes if global warming continues unchecked.
• The stock market crash had cataclysmal effects on the economy.
• The volcanic eruption brought cataclysmal destruction to nearby villages.
• The war marked a cataclysmal shift in the nation’s history.
• Experts predicted cataclysmal flooding if the dam failed.