Finally part of one's purpose? (8)

I believe the answer is:

intheend

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'finally' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'part of one's purpose?' is the wordplay.
'part of' becomes 'in' (I've seen this in other clues).
'one' becomes 'the' (both can introduce a definite example of something).
'purpose?' becomes 'end' (purpose is a kind of end).
'in'+'the'+'end'='INTHEEND'

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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