Knockout a Los Angeles gum-chewer? (5)

I believe the answer is:

koala

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'gum-chewer?' is the definition.
I can't judge whether this definition defines the answer.

'knockout a los angeles' is the wordplay.
'knockout' becomes 'KO' (abbreviation).
'los angeles' becomes 'LA' (abbreviation).
'ko'+'a'+'la'='KOALA'

Can you help me to learn more?

(Other definitions for koala that I've seen before include "Australian animal" , "Australian marsupial which lives on eucalyptus leaves" , "Arboreal marsupial" , "Marsupial "bear"" , "Aussie 'bear'" .)

I've seen this clue in the Sydney Morning Herald.

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