The most common and most likely answer to this crossword clue is the 11 letter word BELLYACHING
I've seen this crossword clue in The Daily Telegraph
B
E
L
L
Y
A
C
H
I
N
G
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 BELLYACHING mean?
BELLYACHING verb- To unnecessarily complain or whine, often about simple matters.
- Whining and complaining, often contrived to evoke pity or shirk responsibility.