Decaf lefty stirred in an unnatural way (10)

I believe the answer is:

affectedly

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'in an unnatural way' is the definition.
I can't tell whether this definition defines the answer.

'decaf lefty stirred' is the wordplay.
'stirred' is an anagram indicator.
'decaf'+'lefty'='decaflefty'
'decaflefty' anagrammed gives 'AFFECTEDLY'.

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(Another definition for affectedly that I've seen is " In a pretentious manner".)

I've seen this clue in The Independent.

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