The most common and most likely answer to this crossword clue is the 5 letter word FAUST
I've seen this crossword clue in The Guardian
F
A
U
S
T
More clues leading to the result FAUST
- Quickly grabbing uniform for opera
- One desperately wanting knowledge very quick to engage university
- One who sold out quickly, not plebeian at heart
- Alchemist, one surrounded by mouldy smell …
- Opera house’s heart breaking rapidly
- Resident of Australia — he made a pact with the devil
- Our group gets into fleshy opera
Buddy explains!
The straight part
We know that "One who sold out" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one who sold out = faust.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.