Give no mention about poison (5)
I believe the answer is:
venom
'poison' is the definition.
(I know that venom is a type of animal toxin)
'give no mention about' is the wordplay.
'about' says the answer is hidden in the clue (the clue goes around or about the answer).
'VENOM' is hidden in the letters of 'give no mention'.
(Other definitions for venom that I've seen before include "Spite: toxin" , "Virulent feeling" , "Poisonous secretion" , "Virulence" , "essential part of The Sting" .)