Rate revised within the playhouse (7)
I believe the answer is:
theatre
'playhouse' is the definition.
(I know that playhouse can be written as theatre)
'rate revised within the' is the wordplay.
'revised' indicates anagramming the letters.
'within' indicates putting letters inside.
'rate' is an anagram of 'eatr'.
'eatr' going within 'the' is 'THEATRE'.
(Other definitions for theatre that I've seen before include "Eg, Oxford's Sheldonian" , "Building for the dramatic arts" , "Room for surgery" , "Part of hospital" , "Scene of military activity" .)