The most common and most likely answer to this crossword clue is the 9 letter word REHEARSAL
I've seen this crossword clue in Independent
R
E
H
E
A
R
S
A
L
More clues leading to the result REHEARSAL
- Tries cutting material in run-through of play
- Listens during actual practice session
- Tries to get into Madrid team’s practice session
- Tries to block genuine preparation for show
- Tries to interrupt football team’s practice
- In which cast hears Lear, perhaps
- Tries the lot again, mostly for practice
- Listen again to Sarah in practice
- Reading magazine nurse leaves after cycling here
- Preparation H gets arse sorted? True about that
Buddy explains!

The straight part
We know that "Preparation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case preparation = rehearsal.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 REHEARSAL mean?
REHEARSAL noun- The practicing of something which is to be performed before an audience, usually to test or improve the interaction between several participating people, or to allow technical adjustments with respect to staging to be done.