The most common and most likely answer to this crossword clue is the 11 letter word FAR-FETCHED
I've seen this crossword clue in Independent
F
A
R
-
F
E
T
C
H
E
D
Buddy explains!
The straight part
We know that "Incredible" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case incredible = far-fetched.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 FAR-FETCHED mean?
FAR-FETCHED adjective- Brought from far away.
- Not likely; difficult to believe.