- Mutually destructive; ruinous or fatal to both sides.
- The climate proved fatal to her health.
- The loss of all my money was fatal to my plan.
- His illness was fatal to our plan.
fatal Fatal Accident Frequency Rates fatalness analysis of landslide Fatal Accident Reduction Effort fatalities from mountain climbing fatal error during installation. fatal cytomegalic inclusion disease fatal bacteria granuloma after trauma fatal casualties vulnerability number fatally planning management and service Fatalities usually come from pneumonia.