The most common and most likely answer to this crossword clue is the 5 plus 7 letter word STAGE WHISPER
I've seen this crossword clue in The Daily Telegraph
S
T
A
G
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P
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More clues leading to the result STAGE WHISPER
- Part of journey by ship leaderless crew ruined – most of us are meant to hear this
- Disgruntled whip’s rage set aside
- Pesters a Whig to change statement to the House
- Something dramatic not everyone will pick up
- Confidence shared by the whole house
- Spectators may pick it up, but not other players, it seems
- Announcement intended for spectators but not players, supposedly
- Production line that’s quietly effective?
- Spare weights must be set aside
- Publicly quiet word with press having failed to hide a woman’s secret?
Buddy explains!
The straight part
We know that "Confidence shared by the whole house" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case confidence shared by the whole house = stage whisper.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.