Offal after time is strong-smelling (5)
I believe the answer is:
tripe
'offal' is the definition.
(I've seen this before)
'after time is strong-smelling' is the wordplay.
'after' means one lot of letters go next to another.
'time' becomes 't'.
'is strong-smelling' becomes 'ripe' (I've seen this before).
't' put next to 'ripe' is 'TRIPE'.
(Other definitions for tripe that I've seen before include "Ruminant's stomach lining" , "Stomach for consumption; nonsense" , "Rubbish (colloq.)" , "Balderdash" , "Bunk" .)