Related Clues:

• Librarian's warning
• Soothe
• ''Put a lid on it!''
• Shut up
• Librarian's admonition
• ''Quiet!''
• 'Be quiet!'
• 'Zip your lip!'
• When repeated, not to be repeated
• Recital rebuke
• Mum's the word
• Shout to a talkative butcher?
• Audience utterance
• "Pipe down!"
• Stunned response