Etonian pal gets drunk with Italian citizen (10)
I believe the answer is:
neapolitan
'italian citizen' is the definition.
(I've seen this before)
'etonian pal gets drunk' is the wordplay.
'gets drunk' indicates an anagram.
'etonian'+'pal'='etonianpal'
'etonianpal' is an anagram of 'NEAPOLITAN'.
'with' acts as a link.
(Other definitions for neapolitan that I've seen before include "21 [ITALIAN]" , "One coming from Campania" , "Italian native" , "Three-coloured ice cream" , "chocolate" .)