Slide of large amounts of snow or stone (9)
I believe the answer is:
avalanche
'slide of large amounts of snow or stone' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for avalanche that I've seen before include "flood" , "heavy snowfall" , "Large mass of sliding snow or stone" , "Landfall" , "Slide of large amounts of snow or stone" .)