Acute cut protecting wicket (6)
I believe the answer is:
shrewd
'acute' is the definition.
(thesaurus)
'cut protecting wicket' is the wordplay.
'cut' becomes 'shred' (I've seen this before).
'protecting' is an insertion indicator.
'wicket' becomes 'w'.
'shred' placed around 'w' is 'SHREWD'.
(Other definitions for shrewd that I've seen before include "sharp" , "Astute, clever" , "Sharp-witted" , "Canny and astute" , "worldly wise" .)