Synonyms of fatal in English:

fatal


See definition of fatal

adjective

1‘a fatal disease’

SYNONYMS
deadly, lethal, mortal, causing death, death dealing, killing
final, terminal, incurable, untreatable, inoperable, malignant
tragic
literary deathly
archaic baneful
ANTONYMS

harmless, superficial

2‘don't make the fatal mistake of assuming others think as you do’

SYNONYMS
disastrous, devastating, ruinous, catastrophic, calamitous, cataclysmic, destructive, grievous, dire, crippling, crushing, injurious, harmful, costly
literary direful
ANTONYMS

harmless, beneficial