Schoolboy son European kicks out (7)

I believe the answer is:

etonian

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'schoolboy' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for etonian that I've seen before include "Pupil at posh English school" , "Public school kid" , "student in establishment?" , "English student" , "Relating to one particular school" .)

I've seen this clue in The Sun.

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