In first act, I clapped skilful manoeuvre (6)
I believe the answer is:
tactic
'manoeuvre' is the definition.
(I know that manoeuvre can be written as tactic)
'in first act i clapped skilful' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TACTIC' is hidden in the letters of 'first act i clapped skilful'.
(Other definitions for tactic that I've seen before include "Device" , "Planned manoeuvre or skilful move" , "Scheme or ploy used in battle, sport, etc, often within an overall strategy" , "A manoeuvre or planned action" , "element of strategy" .)