A disaster is a terrible situation. You can use this word for accidents, damage caused by storms, problems created by mistakes, failed relationships, and poor performances. The word "disaster" is also used for exaggerating problems.
Alfredo’s backyard is a disaster. (It’s very messy.)
The speech given by the candidate was a disaster. (It was a very bad speech.)
The kitchen was a disaster after the children spent the afternoon making cookies.
Keeping a wild animal as a pet is a disaster waiting to happen.
Our city’s police and fire departments are prepared for disasters.
Disaster relief organizations went to Haiti following the earthquake.
The state of Oklahoma requested disaster assistance in the wake of several strong tornadoes that leveled three small towns. (leveled = destroyed)
We’ve noticed a dramatic increase in natural disasters in the last ten years.
It can take weeks or months to clean up after a disaster.
What a disaster!
The word "disastrous" is an adjective:
A disastrous epidemic hit the small village quickly and killed hundreds of people.
Several disastrous decisions caused the paper company to go out of business.
Sarah has had two disastrous relationships in the last few years.
If carbon emissions continue to rise, the effects will be disastrous.