Everything finishes convincingly (3,4,2)

I believe the answer is:

all ends up

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

'everything finishes' is the wordplay.
I cannot quite understand how this works, but
'everything' could be 'all' (all things) and 'all' is found in the answer.
'finishes' could be 'endsup' ('end up' can be a synonym of 'finish') and 'endsup' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in The Times.

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