A drink, to the fit, may be a mere bagatelle! (8)

I believe the answer is:

pintable

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'may be a mere bagatelle' is the definition.
I can't tell whether this definition defines the answer.

'a drink to the fit' is the wordplay.
'a drink' becomes 'pint' (I've seen this before).
'to the fit' becomes 'able' (I've seen this before).
'pint'+'able'='PINTABLE'

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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