Endless money and gold is melted down for coinage (9)
I believe the answer is:
neologism
'for coinage' is the definition.
(synonyms)
'endless money and gold is melted down' is the wordplay.
I cannot quite understand how this works, but
'money' could be 'm' (abbreviation in economics) and 'm' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is present in the answer.
'is' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for neologism that I've seen before include "New word or phrase" , "coinage" , "Brexit maybe" , "Newly coined word" , "Newly-coined word or expression" .)