Definitions of disastrous

1. Disastrousness.

2. Attended with suffering or disaster; very unfortunate; calamitous; ill- fated; as, a disastrous day; a disastrous termination of an undertaking.

3. Unlucky; unfortunate; calamitous; attended with evil results.

4. Unlucky; calamitous.

5. Full of disaster; calamitous; gloomy; dismal.

6. Occasioning loss or injury; unfortunate; unlucky; calamitous.