Worn-out banknote and coppers (3,4)
I believe the answer is:
old bill
'coppers' is the definition.
(I've seen this before)
'worn-out banknote' is the wordplay.
'worn-out' becomes 'old' (I've seen this in another clue).
'banknote' becomes 'bill' (synonyms).
'old'+'bill'='OLD BILL'
'and' is the link.
(Other definitions for old bill that I've seen before include "Coppers" , "Cops" , "pound note?" , "evidence of previous appearances in theatre" , "forgotten account" .)