Heap of snow (5)
I believe the answer is:
drift
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">heap of snow</span>' is the definition.<br/ ><span class="explanation-format__explanation">(snowdrift)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for drift that I've seen before include "Slide" , "Tenor" , "Movement off course or in general" , "Travel without purpose" , "Import" .)