Sudden panicked rush (8)
I believe the answer is:
stampede
'sudden panicked rush' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for stampede that I've seen before include "rush for safety maybe" , "Put to flight" , "Crazy pets made a sudden rush" , "Rapid flight" , "Sudden rush of a panicstricken herd" .)