The most common and most likely answer to this crossword clue is the 10 letter word PROSCENIUM
I've seen this crossword clue in The Guardian
P
R
O
S
C
E
N
I
U
M
More clues leading to the result PROSCENIUM
Buddy explains!

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 PROSCENIUM mean?
PROSCENIUM noun- The stage area between the curtain and the orchestra.
- The stage area immediately in front of the scene building.
- The row of columns at the front the scene building, at first directly behind the circular orchestra but later upon a stage.
- A proscenium arch.