Snow heaped up by wind (5)
I believe the answer is:
drift
'snow heaped up by wind' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for drift that I've seen before include "Be powerless to control movement" , "General trend - current travel" , "Coast" , "Movement off course or in general" , "Bank (of snow)" .)