Raise unstable floor (4)
I believe the answer is:
stun
'floor' is the definition.
(both can mean to shock)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stun that I've seen before include "what a cracker may do?" , "cause amazement" , "Make dazed or numb" , "Surprise greatly or daze" , "Shock into silence" .)