The most common and most likely answer to this crossword clue is the 9 letter word ESTONIANS
I've seen this crossword clue in The Daily Telegraph
E
S
T
O
N
I
A
N
S
More clues leading to the result ESTONIANS
- Baltic people succeeded amongst elite pupils
- Europeans succeeded, interrupting public school types
- Perhaps the PM’s hiding fondness, in the end, for EU members
- Johnson and Cameron, say, bringing in sadness primarily for 18s
- Curious sensation being Russia’s neighbours
- Europeans seeing school head surrounded by pupils
- Pupils at a public school, including small Europeans
- New sensation for Europeans
- Europeans from North and South accepted by chaps of the old school
- Sensation created by Europeans
Buddy explains!

The straight part
We know that "Europeans" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case europeans = estonians.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.