lethal
US /ˈliː.θəl/
UK /ˈliː.θəl/

1.
mortel, fatal
sufficient to cause death
:
•
The snake's venom was lethal.
Le venin du serpent était mortel.
•
He received a lethal dose of radiation.
Il a reçu une dose mortelle de radiations.
2.
fatal, destructeur
harmful or destructive in a significant way
:
•
The company made a lethal mistake in its marketing strategy.
L'entreprise a commis une erreur fatale dans sa stratégie marketing.
•
His criticism was lethal to her confidence.
Sa critique fut fatale à sa confiance.