What someone with a growing concern presumably requires for financing start-up (4,5)
I believe the answer is:
seed money
'growing concern presumably requires for financing start-up' is the definition.
I can't tell whether this defines the answer.
'what someone with a' is the wordplay.
I cannot quite understand how this works, but
'someone' could be 'seed' (seed is a kind of someone) and 'seed' is found within the answer.
'a' could be 'one' and 'one' is found within the answer.
The remaining letters 'my' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for seed money that I've seen is " Funding to initiate a project".)