The most common and most likely answer to this crossword clue is the 5 plus 7 letter word BLOOD DIAMOND
B
L
O
O
D
D
I
A
M
O
N
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.