1. in a manner involving or producing a sudden, violent, and large-scale upheaval or disaster

Examples

• The economy collapsed cataclysmically after the financial crisis.
• The asteroid impact cataclysmically altered Earth's climate.
• The relationship ended cataclysmically when the truth came out.
• The building failed cataclysmically during the earthquake.
• The company's stock price fell cataclysmically in a single trading day.
• The political system shifted cataclysmically following the revolution.