Sailor turning up in parsonage unexpectedly someone you want to see (7,5)

I believe the answer is:

persona grata

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'sailor' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see an association between them that I can't see?

'turning up in parsonage unexpectedly someone you want to see' is the wordplay.
I cannot quite see how this works, but
'someone' could be 'person' (synonyms) and 'person' is found in the answer.
This explanation may well be incorrect...

Can you help me to learn more?

(Another definition for persona grata that I've seen is " One who is diplomatically acceptable".)

I've seen this clue in The Times.

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