Large marsupial (8)
I believe the answer is:
kangaroo
'large marsupial' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for kangaroo that I've seen before include "Native marsupial Down Under" , "Aussie boxer" , "Marsupial from down-under" , "The sort of court" , "One's jumpy" .)