The most common and most likely answer to this crossword clue is the 12 letter word COMPREHENDED
I've seen this crossword clue in Financial Times
C
O
M
P
R
E
H
E
N
D
E
D
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 COMPREHENDED mean?
COMPREHENDED verb- To include, comprise; to contain.
- To understand or grasp fully and thoroughly.
- Understood.
- Included; comprised; contained.