Drama affected the rate (7)
I believe the answer is:
theatre
'drama' is the definition.
(theatre can mean the world of drama)
'affected the rate' is the wordplay.
'affected' is an anagram indicator.
'the'+'rate'='therate'
'therate' is an anagram of 'THEATRE'.
(Other definitions for theatre that I've seen before include "Entertainment venue" , "Playhouse or sphere of action" , "Part of hospital" , "Building for the dramatic arts" , "Space for dramatic art and surgery" .)