The most common and most likely answer to this crossword clue is the 4 letter word BANE
B
A
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The straight part
We know that "curse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case curse = bane.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 BANE mean?
BANE noun- A cause of misery or death.
- Poison, especially any of several poisonous plants.
- A killer, murderer, slayer.
- Destruction; death.
- A disease of sheep.
- To kill, especially by poison; to be the poison of.
- To be the bane of.
- Bone