Admits that snow drifts (4)
I believe the answer is:
owns
'admits' is the definition.
(I've seen this in another clue)
'snow drifts' is the wordplay.
'drifts' indicates an anagram.
'snow' with letters rearranged gives 'OWNS'.
'that' is the link.
(Other definitions for owns that I've seen before include "Has possession of by right" , "Possesses" , "uses" , "Belongs to" , "Admits possession" .)