The most common and most likely answer to this crossword clue is the 1 plus 3 plus 6 letter word A FAT CHANCE
I've seen this crossword clue in The Guardian
A
F
A
T
C
H
A
N
C
E
More clues leading to the result A FAT CHANCE
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.