Burrowing marsupial (6)
I believe the answer is:
wombat
'burrowing marsupial' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for wombat that I've seen before include "Bear-like marsupial" , "Burrowing animal" , "Tailless marsupial down under" , "Australian burrowing marsupial" , "Australian resident" .)