Ruffle caught in chopper turbulence (7)
I believe the answer is:
perturb
'ruffle' is the definition.
(thesaurus)
'caught in chopper turbulence' is the wordplay.
'caught in' indicates a hidden word.
'PERTURB' can be found hidden inside 'chopper turbulence'.
(Other definitions for perturb that I've seen before include "Disturb the composure of" , "Bother" , "Worry" , "Disconcert" , "Make uneasy or cause to be worried" .)