Toxin (6)
'toxin' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for poison that I've seen before include "Eg, toxin" , "[ADDER] 's defence" , "Bane" , "Damaging stuff - drink?" , "Deadly substance" .)
'toxin' is the definition.
(I know that toxin can be written as Venom)
This is all the clue.
(Other definitions for venom that I've seen before include "Poison; malice" , "essential part of The Sting" , "ill will" , "Toxic substance" , "Snake's poison" .)