Stagger, having knocked time off dangerous exploit (4)
I believe the answer is:
stun
'stagger' is the definition.
(both can mean to shock)
'knocked time off dangerous exploit' is the wordplay.
I cannot quite understand how this works, but
'time' could be 't' (abbreviation) and 't' is found within the answer.
The remaining letters 'sun' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'having' is the link.
Can you help me to learn more?
(Other definitions for stun that I've seen before include "Leave speechless" , "Daze, overwhelm" , "Surprise greatly or daze" , "Numb with nuts" , "Shock or astonish" .)