The most common and most likely answer to this crossword clue is the 4 letter word HARM
H
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More clues leading to the result HARM
Buddy explains!

The straight part
We know that "Damage /" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case damage / = harm.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 HARM mean?
HARM noun- Physical injury; hurt; damage
- Emotional or figurative hurt
- Detriment; misfortune.
- That which causes injury, damage, or loss.
- To cause injury to another; to hurt; to cause damage to something.