Definitions of fatal:
- adjective: controlled or decreed by fate; predetermined
Example: "A fatal series of events"
- adjective: bringing death
- adjective: having momentous consequences; of decisive importance
Example: "The fatal day of the election finally arrived"
- adjective: (of events) having extremely unfortunate or dire consequences; bringing ruin
Example: "Such doctrines, if true, would be absolutely fatal to my theory- Charles Darwin"