The most common and most likely answer to this crossword clue is the 10 letter word AMAZEBALLS
I've seen this crossword clue in Independent
A
M
A
Z
E
B
A
L
L
S
More clues leading to the result AMAZEBALLS
Buddy explains!
The straight part
We know that "Fab" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fab = amazeballs.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 AMAZEBALLS mean?
AMAZEBALLS adjective- Amazing.