Trial involving gold trade (6)
I believe the answer is:
ordeal
'trial' is the definition.
(thesaurus)
'gold trade' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'trade' becomes 'deal' ('deal' can be a synonym of 'trade').
'or'+'deal'='ORDEAL'
'involving' is the link.
(Other definitions for ordeal that I've seen before include "A test of endurance or or difficult experience" , "Difficult and painful experience" , "Tough test in Laredo" , "Horrific experience" , "severe test shows" .)