Circulate gold piece (5)
I believe the answer is:
orbit
'circulate' is the definition.
(orbiting is a kind of circulating)
'gold piece' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'piece' becomes 'bit' (synonyms).
'or'+'bit'='ORBIT'
(Other definitions for orbit that I've seen before include "Circle in space" , "Planet's path" , "heavenly passage" , "Area of influence - eye socket" , "field of activity" .)