Theatre reviewer (6)
I believe the answer is:
critic
'theatre reviewer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for critic that I've seen before include "Reviewer of plays, films etc" , "A reviewer of plays, books etc" , "Reviewer - fault-finder" , "One analyses and interprets works of art" , "Judge of literary or artistic works" .)