Officer element (6)
I believe the answer is:
copper
This clue is a double definition.
'officer' is the first definition.
(copper is a kind of officer)
'element' is the second definition.
(copper is a kind of element)
(Other definitions for copper that I've seen before include "Reddish-brown like colourful beech" , "Atomic number 29" , "Part of force" , "Low-value coin" , "Small loose change" .)