The most common and most likely answer to this crossword clue is the 6 letter word DOOMED
I've seen this crossword clue in Independent
D
O
O
M
E
D
More clues leading to the result DOOMED
Buddy explains!

The straight part
We know that "Ill-fated" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ill-fated = doomed.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 DOOMED mean?
DOOMED verb- To pronounce sentence or judgment on; to condemn.
- To destine; to fix irrevocably the ill fate of.
- To judge; to estimate or determine as a judge.
- To ordain as a penalty; hence, to mulct or fine.
- To assess a tax upon, by estimate or at discretion.
- Assured to suffer death, failure, or a similarly negative outcome.