Counterfeiting next year's coins and prospering (7,5)
I believe the answer is:
'prospering' is the definition.
Although both the answer and definition are present participle verbs, I cannot understand how they can define each other.
'counterfeiting next year's coins' is the wordplay.
'counterfeiting' becomes 'forging' ('forge' can be a synonym of 'counterfeit').
'next year's coins' becomes 'ahead' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'and' acts as a link.
Can you help me to learn more?