Trendy art movement censoring sadomasochistic nightmares (6)
I believe the answer is:
incubi
'nightmares' is the definition.
('incubus' can be a synonym of 'nightmare')
'trendy art movement censoring sadomasochistic' is the wordplay.
'trendy' becomes 'in' ('in' can mean fashionable).
'art movement' becomes 'cubism' (cubism was an art movement).
'censoring' is a deletion indicator.
'sadomasochistic' becomes 'SM' (S and M means sadism and masochism).
'cubism' with 'sm' taken out is 'cubi'.
'in'+'cubi'='INCUBI'
(Other definitions for incubi that I've seen before include "Demons of the night" , "nightmares" .)