Related Clues:

• 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?
• 'Not a peep!'
• 'Stop talking!'
• Hush!
• "Too noisy!"
• 'Shh!'
• Classroom reminder
• Button it!