Credit note gets money for a fool (6)
I believe the answer is:
cretin
'a fool' is the definition.
(thesaurus)
'credit note gets money' is the wordplay.
'credit' becomes 'cr'.
'note' becomes 'e' (musical note).
'gets' says to put letters next to each other.
'money' becomes 'tin' (I've seen this before**).
'cr'+'e'+'tin'='CRETIN'
'for' is the link.
(Other definitions for cretin that I've seen before include "Charlie" , "Halfwit" , "Idiot!" , "soft" , "fool" .)