"Short dwarf" shock (4)
I believe the answer is:
stun
'shock' is the definition.
('stun' can be a synonym of 'shock')
'short dwarf' is the wordplay.
'short' means to remove the last letter.
'dwarf' becomes 'stunt' (I've seen this before).
'stunt' with its last letter removed is 'STUN'.
(Other definitions for stun that I've seen before include "Knock out temporarily" , "Amaze; knock senseless" , "cause amazement" , "Surprise greatly, knock someone''s socks off" , "Daze or bewilder" .)