Catastrophe is a disaster on a larger scale, destroying most or all means to fight it, including the extinction of whole societies.

The Univeristy of Delaware's Disaster Research Center differentiates disasters from emergencies and catastrophes as follows:

• Emergency: An event that may be managed locally without the need of added response measures or changes to procedure.
• Disaster: An event that,

1. involves more groups who normally do not need to interact in order to manage emergencies
2. requires involved parties to relinquish the usual autonomy & freedom to special response measures and organizations
3. changes the usual performance measures, and
4. requires closer operations between public and private organizations.

• Catastrophe: An event that,

1. destroys most of a community
2. prevents local officials performing their duties
3. causes most community functions cease, and
4. prevents adjacent communities from providing aid. [1]

In the insurance field, a catastrophe is a disaster beyond expectations. For instance, the insurance industry can calculate the expected damage from hurricanes in a specific location for a particular year. A catastrophic hurricane causes loss of life and property beyond the calculations.

In the field of sociology it is defined as social change of an outstanding radical and rapid character, with highly magical explanations by victims and others.

As a technical term "catastrophic failure" may simply mean that something breaks, etc. Also the term occurs as error message on a computer.

In mathematics, catastrophe theory studies how the behaviour of dynamical systems can change drastically with variations in certain parameters.