Tom Paine accepts consequence of decay (8)
I believe the answer is:
ptomaine
'consequence of decay' is the definition.
(I've seen this before)
'tom paine accepts' is the wordplay.
'accepts' means one lot of letters goes inside another.
'tom' put into 'paine' is 'PTOMAINE'.
(Other definitions for ptomaine that I've seen before include "poison!" , "Consequence of decay" , "Poisoning, for instance" , "Pain to me (anag.)" , "A pimento might turn to food poisoning" .)