The most common and most likely answer to this crossword clue is the 5 letter word ASIDE
I've seen this crossword clue in Financial Times
A
S
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More clues leading to the result ASIDE
Buddy explains!
The straight part
We know that "line directed at the audience" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case line directed at the audience = aside.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 ASIDE mean?
ASIDE noun- An incidental remark made quietly so as to be heard by the person to whom it is said and not by any others in the vicinity.
- A brief comment by a character addressing the audience, unheard by other characters.
- A minor related mention, an afterthought.
- To or on one side so as to be out of the way.