One represents clients in court (9)
I believe the answer is:
barrister
'one represents clients in court' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for barrister that I've seen before include "member of an inn" , "Lawyer for the higher courts" , "Rarest rib for the eminent lawyer" , "Legal representative" , "American lawyer" .)