Applaud revolutionary role? Nonsense (8)
I believe the answer is:
claptrap
'nonsense' is the definition.
(informal term meaning nonsense or rubbish)
'applaud revolutionary role?' is the wordplay.
'applaud' becomes 'clap' (synonyms).
'revolutionary' shows that the letters should be reversed in order (letters revolve around).
'role?' becomes 'part' (eg a part or role in a film).
'part' written backwards gives 'trap'.
'clap'+'trap'='CLAPTRAP'
(Other definitions for claptrap that I've seen before include "Contrived but foolish talk" , "Pretentious talk or nonsense" , "poppycock" , "Applaud snare? - that's pretentious nonsense" , "Bull" .)