A charge that makes you feel robbed of pounds? (3)
I believe the answer is:
fee
'a charge' is the definition.
(I know that fee is a type of fixed charge)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for fee that I've seen before include "Payment to a professional for services" , "Sum payable to professional person for services" , "(Entry) charge" , "Cost" , "Sum payable to, say, barrister" .)