Enquiry ended early on ring with no charges (3,4)
I believe the answer is:
pro bono
'with no charges' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pro bono that I've seen before include "Giving free services" , "not being paid" , "For the public good - ... .... publico" , "Done for the public good unpaid" , "with no charges" .)