Some characters seethe at repositioning of auditorium (7)
I believe the answer is:
theatre
'auditorium' is the definition.
(I've seen this before)
'some characters seethe at repositioning' is the wordplay.
'some characters' says the answer is hidden in the clue (some letters or characters from the clue).
'THEATRE' is hidden within 'seethe at repositioning'.
'of' is the link.
(Other definitions for theatre that I've seen before include "Globe, say" , "Drama venue" , "Site of plays or surgery" , "where people go to watch" , "Where you might find ham" .)