Breaking violently into pieces (8)
I believe the answer is:
smashing
'breaking violently into pieces' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for smashing that I've seen before include "2 [COOL] or 3 [DANDY] perhaps, possibly 20d [WICKED] or 22 [GEAR] !" , "Such destructive behaviour" , "use for plates at a Greek wedding?" , "Producing tennis shot" , "Breaking violently into pieces" .)