Sausage regrettably returned with note (6)
I believe the answer is:
salami
'sausage' is the definition.
(I know that salami is a type of sausage)
'regrettably returned with note' is the wordplay.
'regrettably' becomes 'alas' ('alas' is said before regrettable news).
'returned' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'note' becomes 'mi' (as in 'do re mi').
'alas' backwards is 'sala'.
'sala'+'mi'='SALAMI'
(Other definitions for salami that I've seen before include "Preserved meat sausage" , "One kind of tactics" , "meat product" , "Spiced Italian sausage" , "Highly seasoned fatty sausage" .)