Chap in those theatres (4)
I believe the answer is:
seth
'chap' is the definition.
'in those theatres' is the wordplay.
'in' indicates a hidden word.
'SETH' can be found hidden inside 'those theatres'.
(Other definitions for seth that I've seen before include "Old Testament character" , "Adam and Eve's third son" , "Cain/Abel brother" , "Third son of Adam and Eve" , "Indian writer" .)