Floor rolled back for enthusiasts (4)
I believe the answer is:
nuts
'enthusiasts' is the definition.
(nut can mean an enthusiast or fan)
'floor rolled back' is the wordplay.
'floor' becomes 'stun' (both can mean to shock).
'rolled back' is a reversal indicator.
'stun' back-to-front is 'NUTS'.
'for' is the link.
(Other definitions for nuts that I've seen before include "Eg, filberts, hazels" , "Fruit with edible kernel" , "Hard-shelled fruit" , "Metal fasteners" , "Nibbles" .)