The most common and most likely answer to this crossword clue is the 9 letter word UNMATCHED
I've seen this crossword clue in The Sunday Telegraph
U
N
M
A
T
C
H
E
D
More clues leading to the result UNMATCHED
Buddy explains!

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 UNMATCHED mean?
UNMATCHED verb- To separate a matching pair.
- (of a pair of things) not matched; odd
- (of a single thing) not matched with anything else
- Peerless; unrivalled; beyond comparison