The most common and most likely answer to this crossword clue is the 11 letter word ARISTOCRATS
I've seen this crossword clue in The Guardian
A
R
I
S
T
O
C
R
A
T
S
Buddy explains!

The straight part
We know that "Peers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case peers = aristocrats.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 ARISTOCRATS mean?
ARISTOCRATS noun- One of the aristocracy, nobility, or people of rank in a community; one of a ruling class; a noble (originally in Revolutionary France).
- A proponent of aristocracy; an advocate of aristocratic government.