Glow in arcade explosively (8)
I believe the answer is:
radiance
'glow' is the definition.
(I know that glow can be written as radiance)
'in arcade explosively' is the wordplay.
'explosively' indicates anagramming the letters.
'in'+'arcade'='inarcade'
'inarcade' anagrammed gives 'RADIANCE'.
(Other definitions for radiance that I've seen before include "Refulgence" , "Joyful splendour" , "Brightness" , "moonlight" , "A bright glow (E, not Y)" .)