Torn anorak? Go get a jumper! (8)
I believe the answer is:
Here is my best explanation:
'a jumper' is the definition.
'torn anorak? go' is the subsidiary indication.
'torn' is an anagram indicator.
'anorakgo' is an anagram of 'kangaroo'.
'get' is the link.
(Other definitions for kangaroo that I've seen before include "Hopping marsupial", "Leaping marsupial from Down Under", "Marsupial that boxes", "Leaping mammal", "Marsupial from down-under", "Jumper of grey or red", "A marsupial", "Pouched mammal", "Aussie boxer" and "impromptu kind of court".)