Reddish metallic element (6)
I believe the answer is:
copper
'reddish metallic element' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for copper that I've seen before include "Coin, policeman or metallic element" , "Reddish metallic element" , "Ductile metal" , "Metal - wash basin" , "Low-value coin" .)