Good wearing torn anorak and ordinary jumper (8)
I believe the answer is:
kangaroo
'jumper' is the definition.
(I've seen this before)
'good wearing torn anorak and ordinary' is the wordplay.
'good' becomes 'g' (abbreviation).
'wearing' means one lot of letters goes inside another.
'torn' indicates an anagram.
'and' says to put letters next to each other.
'ordinary' becomes 'O' (abbreviation eg in O-Level, Ordinary Level).
'anorak' anagrammed gives 'kanaro'.
'g' put inside 'kanaro' is 'kangaro'.
'kangaro'+'o'='KANGAROO'
(Other definitions for kangaroo that I've seen before include "Pouched mammal" , "Illegal court of marsupial origin?" , "Large Australian mammel" , "Antipodean marsupial" , "Native marsupial Down Under" .)