Applaud role reversal? Nonsense (8)
I believe the answer is:
claptrap
'nonsense' is the definition.
(I've seen this before)
'applaud role reversal?' is the wordplay.
'applaud' becomes 'clap' (synonyms).
'role' becomes 'part' (synonyms).
'reversal?' says the letters should be written in reverse (I've seen 'reversal of' mean this).
'part' reversed gives 'trap'.
'clap'+'trap'='CLAPTRAP'
(Other definitions for claptrap that I've seen before include "Tripe" , "Meaningless nonsense" , "Absurd or nonsensical talk or ideas" , "Pretentious rot" , "High-sounding nonsense" .)