The most common and most likely answer to this crossword clue is the 7 plus 6 letter word FEEDING FRENZY
I've seen this crossword clue in Independent
F
E
E
D
I
N
G
F
R
E
N
Z
Y
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.