The most common and most likely answer to this crossword clue is the 7 letter word FIDDLER
I've seen this crossword clue in Independent
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More clues leading to the result FIDDLER
- Musician, a cheat
- Fine supplier of puzzles, overlooking first one cheating
- Musician — one with a racket
- One keeping records about theologian, one who interferes
- One going with female for party leader is a fraud
- Cheat plays field, nicking diamonds and rupees
- Musician involved in a racket?
- Violinist, one engaged in questionable practice
- Force lazybones to acquire degree as musician
- Musician, untrustworthy type
Buddy explains!

The straight part
We know that "Violinist/one engaged in questionable practice" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case violinist/one engaged in questionable practice = fiddler.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 FIDDLER mean?
FIDDLER noun- One who plays the fiddle.
- One who fiddles.
- A burrowing crab of the genus Gelasimus, of many species. The male has one claw very much enlarged, and often holds it in a position similar to that in which a musician holds a fiddle.
- The common European sandpiper (Actitis hypoleucos); so called because it continually oscillates its body.