Query girl messing around with oddly sweary American interloper (4,8)

I believe the answer is:

grey squirrel

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'american interloper' is the definition.
The definition suggests a singular noun which matches the answer.

'query girl messing around with oddly sweary' is the wordplay.
'messing around with' is an anagram indicator.
'oddly' means one should take alternating letters (letters in odd-numbered positions).
The alternating letters of 'sweary' are 'ser'.
'query'+'girl'='querygirl'
'querygirl' anagrammed with 'ser' can make 'GREY SQUIRREL'.

Can you help me to learn more?

(Other definitions for grey squirrel that I've seen before include "Common arboreal rodent, originally from America" , "Bushy-tailed North America rodent, now a UK pest" .)

I've seen this clue in The Irish Times.

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