Rule that it’s gold and I prove to be wrong (6)
I believe the answer is:
ordain
'rule' is the definition.
(I've seen this before)
'it's gold and i prove to be wrong' is the wordplay.
I cannot really see how this works, but
'gold' could be 'or' ('or' is the heraldic name for gold) and 'or' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
'i' could be 'a' and 'a' is found in the answer.
The remaining letters 'di' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'that' acts as a link.
Can you help me to learn more?
(Other definitions for ordain that I've seen before include "Decree or consecrate" , "Make someone a clergyman" , "Decree or appoint to priesthood" , "Appoint - admit to holy orders" , "Invest with priestly authority" .)