Zinc or copper (5)
I believe the answer is:
metal
I believe this clue is a double definition.
'zinc' is the first definition.
(thesaurus)
'copper' is the second definition.
(I've seen this before)
(Other definitions for metal that I've seen before include "Broken stone used in road-making" , "Copper or silver, say" , "Gambling token" , "Iron, for instance" , "lead as one" .)