The most common and most likely answer to this crossword clue is the 2 plus 7 letter word IN THEATRE
I
N
T
H
E
A
T
R
E
Buddy explains!
The straight part
We know that "Being cut up/during West End run?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case being cut up/during west end run? = in theatre.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.