Neat, polite and not totally Italian (10)
I believe the answer is:
neapolitan
'italian' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
(Other definitions for neapolitan that I've seen before include "From Naples" , "One coming from Campania" , "Three-coloured ice cream" , "Italian native" , "21 [ITALIAN]" .)