The most common and most likely answer to this crossword clue is the 6 letter word GENTRY
I've seen this crossword clue in The Times
G
E
N
T
R
Y
More clues leading to the result GENTRY
- Aristocracy’s grand record
- General test for upper classes
- Posh people experiment with dope
- Dope experiment produces pretty high people
- The privileged and the low-down judge
- Good access for aristocracy
- Information on test for posh class?
- Given facts, tax the upper classes
- Good first appearance needed for the upper crust
- Knowledge test for the upper classes
Buddy explains!

The straight part
We know that "Posh people" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case posh people = gentry.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.
What does GENTRY mean?
GENTRY noun- Birth; condition; rank by birth.
- Courtesy; civility; complaisance.
- People of education and good breeding.
- In a restricted sense, those people between the nobility and the yeomanry.