Amaze by throwing nuts (4)
I believe the answer is:
stun
'amaze' is the definition.
(to stun is to amaze or shock)
'throwing nuts' is the wordplay.
'throwing' indicates an anagram (letters get thrown around).
'nuts' with letters rearranged gives 'STUN'.
'by' is the link.
(Other definitions for stun that I've seen before include "Daze, paralyse" , "Daze, render semi-conscious" , "Leave speechless" , "Render temporarily senseless" , "Take aback" .)