Artist using copper (9)
I believe the answer is:
constable
I believe this clue is a double definition.
'artist' is the first definition.
(I've seen this before)
'copper' is the second definition.
(thesaurus)
'using' acts as a link.
(Other definitions for constable that I've seen before include "Did he have a brush" , "PC" , "Law enforcer" , "In England, a great painter or lowly policeman" , "the governor of a royal castle" .)