Cockney’s shed tears to stun old bounder (8)
I believe the answer is:
kangaroo
'bounder' is the definition.
(animal which bounds around)
'cockney's shed tears to stun old' is the wordplay.
'cockney's shed' becomes ''angar' ('hangar' - both can mean a storage area - said with the 'H' dropped - a cockney accent.).
'tears' is an insertion indicator (some letters tear into others).
'to stun' becomes 'KO' (knock out in boxing).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'angar' inserted into 'ko' is 'kangaro'.
'kangaro'+'o'='KANGAROO'
(Other definitions for kangaroo that I've seen before include "Marsupial that boxes" , "Antipodean marsupial" , "Bounding marsupial" , "Would anorak go on the animal?" , "Leaping marsupial" .)