disaster
Concise Oxford English Dictionary © 2008 Oxford University Press:
disaster/dɪˈzɑːstə(r)/
▶noun
- 1 a sudden accident or a natural catastrophe that causes great damage or loss of life.
- 2 an event or fact leading to ruin or failure.
■ informal a complete failure: my perm is a total disaster.
– origin C16: from Ital. disastro ‘ill-starred event’, based on L. astrum ‘star’.
'disaster' also found in these Oxford entries:

