Go off tripe (3)
I believe the answer is:
rot
This clue is a double definition.
'go off' is the first definition.
(as in food going off)
'tripe' is the second definition.
(I've seen this in another clue)
(Other definitions for rot that I've seen before include "Cobblers" , "Decay - rubbish" , "Drivel" , "Decay, perish" , "Balderdash" .)