The most common and most likely answer to this crossword clue is the 2 plus 8 letter word BE PREPARED
I've seen this crossword clue in The Daily Telegraph
B
E
P
R
E
P
A
R
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.