French life missing one French name for poison (5)
I believe the answer is:
venom
'for poison' is the definition.
(venom is a kind of poison)
'french life missing one french name' is the wordplay.
I cannot really see how this works, but
an anagram of 'one' is 'eno' which is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for venom that I've seen before include "essential part of The Sting" , "Bitter malice" , "bitterness" , "Virulence" , "Poisonous fluid" .)