Poison that makes some live no more (5)
I believe the answer is:
venom
'poison' is the definition.
(I know that venom is a type of animal toxin)
'some live no more' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'VENOM' is hidden in the letters of 'live no more'.
'that makes' acts as a link.
(Other definitions for venom that I've seen before include "acrimony" , "Poisonous fluid" , "Spite: toxin" , "Bitter malice" , "Virulence" .)