The most common and most likely answer to this crossword clue is the 13 letter word CONCUPISCENCE
C
O
N
C
U
P
I
S
C
E
N
C
E
More clues leading to the result CONCUPISCENCE
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 CONCUPISCENCE mean?
CONCUPISCENCE noun- An ardent desire, especially sexual desire; lust.