The most common and most likely answer to this crossword clue is the 2 letter word AM
I've seen this crossword clue in The Daily Telegraph
A
M
Buddy explains!
The straight part
We know that "actors in this?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case actors in this? = am.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 AM mean?
AM adverb- Before noon.