Circulate gold coin (5)
I believe the answer is:
orbit
'circulate' is the definition.
(orbiting is a kind of circulating)
'gold coin' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'coin' becomes 'bit' (I've seen this before).
'or'+'bit'='ORBIT'
(Other definitions for orbit that I've seen before include "field of activity" , "E.g. planetary movement" , "Circumgyration" , "Path of planet around sun" , "heavenly passage" .)