The most common and most likely answer to this crossword clue is the 6 letter word FIENDÂ
I've seen this crossword clue in The Guardian
F
I
E
N
D
Â
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 FIENDÂ mean?
FIENDÂ noun- A devil or demon; a malignant or diabolical being; an evil spirit.
- A very evil person.
- An enemy; a foe.
- The enemy of mankind, specifically, the Devil; Satan.
- An addict or fanatic.
- To yearn; to be desperate (for something).