Related Clues:

• Be quiet!
• Sound heard in a movie theater
• Library warning
• Whisperer's reproof
• Sound of silence?
• "That's enough out of you!"
• 'Shut your word hole'
• ''Zip it!''
• Librarian's reminder
• 'Don't let them hear us!'
• Volume control?
• "Too noisy!"
• "Cut the chatter!"
• "Shaddap!"
• Audible silencer