Poland-America by United? Take me with you! (4-3)

I believe the answer is:

plus-one

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

'poland-america by united?' is the wordplay.
'poland' becomes 'PL' (e.g. on number plates).
'america' becomes 'US' (United States).
'by' says to put letters next to each other.
'united?' becomes 'one' (as in a phrase like 'we are one').
'pl'+'us'+'one'='PLUS-ONE'

'take' is the link.

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I've seen this clue in The Independent.

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