1. operating with minimal human intervention; independent of external control
- automatic transmission
- a budget deficit that caused automatic spending cuts
2. resembling the unthinking functioning of a machine
- an automatic `thank you'
3. without volition or conscious control
- the automatic shrinking of the pupils of the eye in strong light
Sentences with automatic as an adjective:
- The automatic clothes washer was a great labor-saving device
- The reaction was automatic: flight!