Meat product I'm unfortunately returning (6)
I believe the answer is:
salami
'meat product' is the definition.
(I've seen this before)
'i'm unfortunately returning' is the wordplay.
'unfortunately' becomes 'alas' ('alas' is used to express regret).
'returning' is a reversal indicator.
'im'+'alas'='imalas'
'imalas' written backwards gives 'SALAMI'.
(Other definitions for salami that I've seen before include "Food" , "One kind of tactics" , "Highly seasoned Italian sausage" , "Italian garlic sausage" , "Spicy preserved sausage" .)