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

The straight part
We know that "Impresarios" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case impresarios = producers.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 PRODUCERS mean?
PRODUCERS noun- An individual or organization that creates goods and services.
- One who produces an artistic production like a CD, a theater production, a film, a TV program and so on.
- An organism that produces complex organic compounds from simple molecules and an external source of energy.
- An arrest for speeding after which the driver is allowed seven days (or ten, in the Republic of Ireland) in which to produce his/her driving licence and related documents at a police station.
- A furnace for producing combustible gas for fuel.