A gold-coloured alloy of copper, tin, or zinc used to decorate furniture, mouldings, etc (6)
I believe the answer is:
ormolu
(Other definitions for ormolu that I've seen before include "Gold-coloured alloy used in ornamentation" , "Gold-coloured alloy used for decorating furniture etc" , "Ornamental gold alloy" , "Gilt brass" , "Gold-coloured alloy used to decorate furniture" .)