Agent's cut (3)
I believe the answer is:
fee
'agent's cut' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for fee that I've seen before include "Cost" , "Sum payable to professional person for services" , "Payment to a professional for services" , "Sum payable to, say, barrister" , "Money paid for professional services" .)