The most common and most likely answer to this crossword clue is the 10 letter word UNENVIABLE
I've seen this crossword clue in The Sunday Telegraph
U
N
E
N
V
I
A
B
L
E
More clues leading to the result UNENVIABLE
Buddy explains!

The straight part
We know that "Not appealing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case not appealing = unenviable.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 UNENVIABLE mean?
UNENVIABLE adjective- Difficult, undesirable, or unpleasant; not to be envied.