Stagger out to lunch in wrong direction (4)
I believe the answer is:
stun
'stagger' is the definition.
(both can mean to shock)
'to lunch in wrong direction' is the wordplay.
'to lunch in wrong' becomes 'stu' (I can't explain this - if you can you should give a lot more credence to this answer).
'direction' becomes 'N' (compass direction north).
'stu'+'n'='STUN'
'out' is the link.
Can you help me to learn more?
(Other definitions for stun that I've seen before include "Daze, overwhelm" , "Knock cold" , "Bowl over" , "Numb with nuts" , "Render insensitive" .)