Different from gold, debt instruments reportedly untrustworthy (9)
I believe the answer is:
notorious
'reportedly untrustworthy' is the definition.
I can't tell whether this defines the answer.
'different from gold debt instruments' is the wordplay.
'different from' becomes 'not' (I can't explain this - if you can you should give a lot more credence to this answer).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'debt instruments' becomes 'IOUs' (IOU is an example).
'not'+'or'+'ious'='NOTORIOUS'
Can you help me to learn more?
(Other definitions for notorious that I've seen before include "Undesirably well-known" , "Having a bad name" , "Famous for misdeeds" , "Famous for something bad" , "Famous for bad deeds" .)