Feathers twist into sudden declines (9)

I believe the answer is:

downturns

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'sudden declines' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'feathers twist into' is the wordplay.
'feathers' becomes 'downs' (down is a kind of feather).
'twist' becomes 'turn' (synonyms).
'into' indicates putting letters inside.
'downs' enclosing 'turn' is 'DOWNTURNS'.

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

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