The most common and most likely answer to this crossword clue is the 7 letter word ETONIAN
I've seen this crossword clue in Independent
E
T
O
N
I
A
N
More clues leading to the result ETONIAN
- Public school pupil recalled mark given to Scottish lad
- PM perhaps somehow contained spending limits?
- Public school type's rising importance in surrounding area
- Mark’s repelled by terrible Russian, not Victor — Boris?
- Baltic citizen taking son out of posh school?
- . . . . where resident avoids small schoolboy
- Briefly anointed barbarous Boris Johnson?
- Eg Boris‘s message rejected by Scotsman
- Schoolboy to back Botham getting bowled out
- Peashooters finally confiscated from European student
Buddy explains!
The straight part
We know that "of posh school?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case of posh school? = etonian.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.