Important potential groom accepts new source of funding (4,7)
I believe the answer is:
high finance
'important potential groom accepts new' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'source of funding' is the wordplay.
'source of' becomes 'high' (I can't explain this - if you can you should give a lot more credence to this answer).
'funding' becomes 'finance' (I've seen this before).
'high'+'finance'='HIGH FINANCE'
Can you help me to learn more?
(Other definitions for high finance that I've seen before include "management of large sums" , "Large, complex (and shady?) money transactions" .)