The most common and most likely answer to this crossword clue is the 6 letter word NOBLES
N
O
B
L
E
S
More clues leading to the result NOBLES
Buddy explains!

The straight part
We know that "aristocracy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case aristocracy = nobles.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 NOBLES mean?
NOBLES noun- An aristocrat; one of aristocratic blood.
- A medieval gold coin of England in the 14th and 15th centuries, usually valued at 6s 8d.