Finish last pieces of stale Italian bread (3)
I believe the answer is:
end
'finish' is the definition.
(synonyms)
'last pieces of stale italian bread' is the wordplay.
'last pieces of' indicates one should take the final letters (I've seen 'last piece of' mean this).
The final letters of 'stale italian bread' are 'END'.
(Other definitions for end that I've seen before include "Purpose, objective" , "Unyielding" , "Butt" , "'Conclusion, finale (3)'" , "Remainder" .)