The most common and most likely answer to this crossword clue is the 9 letter word IMPOSTURE
I've seen this crossword clue in The Times
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More clues leading to the result IMPOSTURE
Buddy explains!

The straight part
We know that "fraud" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fraud = imposture.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 IMPOSTURE mean?
IMPOSTURE noun- The act or conduct of an impostor; deception practiced under a false or assumed character; fraud or imposition