Debauched Saturnalia in the Antipodes (10)

I believe the answer is:

australian

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'the antipodes' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.

'debauched saturnalia' is the wordplay.
'saturnalia' can be anagrammed to 'AUSTRALIAN'.
Though, I'm not sure how this is indicated.

'in' acts as a link.

Can you help me to learn more?

(Other definitions for australian that I've seen before include "Sydney native" , "Person from down under" , "Digger" , "Perhaps Victorian" , "Antipodean" .)

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

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