Smack on the wrist? (4)
I believe the answer is:
cuff
This clue is a double definition.
'smack' is the first definition.
(both can mean to hit)
'on the wrist?' is the second definition.
(I've seen this before)
(Other definitions for cuff that I've seen before include "Sleeve ending" , "Turned-back hem to sleeve" , "Blow; end of sleeve" , "Blow - it's on shirt!" , "by one hand" .)