World of the theatre? (5)
I believe the answer is:
globe
I believe this clue is a double definition.
'world' is the first definition.
('globe' can be a synonym of 'world')
'the theatre?' is the second definition.
(I've seen this before)
'of' is the link.
(Other definitions for globe that I've seen before include "Orb, ball" , "stage for Shakespeare" , "Earth - sphere" , "The round world" , "Rounded object" .)