Bank deposit? (4)
(Other definitions for sand that I've seen before include "George -, Fr. author" , "Desert grit" , "Desert material" , "Shore grain" , "Rub down (for painting)" .)
'bank deposit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for silt that I've seen before include "Sedimentary deposit" , "Jamboree" , "Fine river sediment" , "Mud deposits in a river" , "Sediment in a stream" .)
(Other definitions for snow that I've seen before include "Cold precipitation" , "Frozen rain" , "Winter precipitation a cocaine" , "Frozen flakes" , "Spring flower" .)