Clever about it in a proper way (5)

I believe the answer is:

fitly

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'in a proper way' is the definition.
I can't tell whether this definition defines the answer.

'clever about it' is the wordplay.
'clever' becomes 'fly'.
'about' is an insertion indicator.
'fly' going around 'it' is 'FITLY'.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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