A catastrophe is a terrible disaster that causes serious damage, destruction, or suffering. When a massive earthquake strikes a city, or a hurricane floods entire neighborhoods, those are catastrophes. A catastrophe is something truly devastating that affects many people's lives, something far beyond small problems or minor setbacks.

Today we use it for real disasters: the sinking of the Titanic was a catastrophe, and massive forest fires that destroy thousands of homes are catastrophes.

People also use the word more casually for smaller disasters. A student might call a failed science experiment a catastrophe, or say their messy room is catastrophic. But true catastrophes involve serious harm: famines, major floods, devastating wars, or accidents that kill many people.

The adjective form is catastrophic, describing something that causes or relates to a catastrophe. A catastrophic failure means something broke down completely and dangerously, not just a small malfunction. When something goes catastrophically wrong, the results are disastrous and often irreversible.