The most common and most likely answer to this crossword clue is the 6 letter word HOODOO
I've seen this crossword clue in The Daily Telegraph
H
O
O
D
O
O
More clues leading to the result HOODOO
- Gangster rings, causing bad luck
- Curse which people perform out loud
- Curse rings that gangster’s put on
- . Jinx violent criminal over nothing
- Gangster ducks bad luck
- Charming activity of husband, putting diamonds in rings
- Gangster rings? That’s bad luck
- Bringer of bad luck in gangster circles
- Loves wearing different red suits, plus spectacles for a spell
- Violent criminal loves to cause misfortune
Buddy explains!

The straight part
We know that "spell" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case spell = hoodoo.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 HOODOO mean?
HOODOO noun- A practitioner of voodoo.
- Supernatural bad luck, or something or someone believed to bring bad luck.
- A tall thin spire of rock that protrudes from the bottom of arid basins and badlands.
- To jinx; to bring bad luck or misfortune to.