Furniture you’ll find in different sorts of theatre (7)
I believe the answer is:
dresser
This clue is a double definition.
'furniture' is the first definition.
(dresser is a kind of furniture)
'you'll find in different sorts of theatre' is the second definition.
(backstage dressers or operating theatre dressers)
(Other definitions for dresser that I've seen before include "Open-shelved cupboard for displaying dishes" , "help in the theatre" , "One who treats wounds" , "another" , "Chest of drawers" .)