Wave about; flourish (8)
I believe the answer is:
brandish
I believe this clue is a double definition.
'wave about' is the first definition.
(I've seen this in another clue)
'flourish' is the second definition.
(I know that flourish can be written as brandish)
(Other definitions for brandish that I've seen before include "Wave something about threateningly" , "parade" , "Wave, flourish" , "Wave (weapon) aggressively" , "Flourish (a weapon)" .)