The most common and most likely answer to this crossword clue is the 4 plus 10 letter word LIVE AMMUNITION
I've seen this crossword clue in The Guardian
L
I
V
E
A
M
M
U
N
I
T
I
O
N
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.