Meaning of “fatal” - Learner’s Dictionary

fatal

adjective uk us /ˈfeɪtəl/
CAUSING DEATH

B2 A fatal accident or illness causes death:

a fatal car crash
CAUSING PROBLEMS

B2 Fatal actions have very bad effects:

a fatal error
fatally adverb

fatally injured

(Definition of “fatal” from the Cambridge Learner’s Dictionary © Cambridge University Press)