Circulation of gold coin (5)
I believe the answer is:
orbit
'circulation' is the definition.
(orbiting something is circling it)
'gold coin' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'coin' becomes 'bit' (term for various historical coins).
'or'+'bit'='ORBIT'
'of' is the link.
(Other definitions for orbit that I've seen before include "Sphere of action" , "E.g. planetary movement" , "Path of planet etc" , "Range of influence" , "Circle in space" .)