Lawyer may see obstruction placed across street (9)
I believe the answer is:
barrister
'lawyer' is the definition.
(barrister is a kind of lawyer)
'obstruction placed across street' is the wordplay.
'obstruction' becomes 'barrier' (barrier is a kind of obstruction).
'placed across' indicates putting letters inside.
'street' becomes 'st'.
'barrier' placed around 'st' is 'BARRISTER'.
'may see' is the link.
(Other definitions for barrister that I've seen before include "Legal counsel" , "Rarest rib for the eminent lawyer" , "Legal representative" , "Legal advocate, must be briefed" , "One represents clients in court" .)