Feathers below Australasia? (9)

I believe the answer is:

downunder

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'australasia?' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'feathers below' is the wordplay.
'feathers' becomes 'down' (down can mean bird feathers).
'below' becomes 'under' (synonyms).
'down'+'under'='DOWNUNDER'

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

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