Piece of chow, perhaps, unsmoked (3-3)
I believe the answer is:
dog-end
'piece' is the definition.
Both the answer and definition are singular nouns.
Maybe there's a link between them I don't understand?
'chow perhaps unsmoked' is the wordplay.
'chow perhaps' becomes 'dog' (chow is a kind of dog).
'unsmoked' becomes 'end' (I can't explain this - if you can you should believe this answer much more).
'dog'+'end'='DOG-END'
'of' is the link.
Can you help me to learn more?
(Another definition for dog-end that I've seen is " Cigarette butt".)