The most common and most likely answer to this crossword clue is the 6 letter word MORBID
I've seen this crossword clue in The Guardian
M
O
R
B
I
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.
What does MORBID mean?
MORBID adjective- Of, or relating to disease.
- (by extension) Taking an interest in unhealthy or unwholesome subjects such as death, decay, disease.
- Suggesting the horror of death; macabre or ghoulish
- Grisly or gruesome.