Brandish roller? (4)
I believe the answer is:
wave
I believe this is a double definition.
'brandish' is the first definition.
(I know that brandish can be written as wave)
'roller?' is the second definition.
(roller is a kind of wave)
(Other definitions for wave that I've seen before include "Greeting; undulation" , "60s cinematic movement with 1a [NEW]" , "Billow" , "Roller, move to and fro" , "Brandish" .)