Related Clues:

• When doubled, confidential
• 'Ixnay!'
• The sound of ''Silence!''
• 'Quiet, please!'
• 'Shush!'
• Librarian's warning
• Soothe
• ''Put a lid on it!''
• Shut up
• Librarian's admonition
• ''Quiet!''
• ''Enough!''
• 'Be quiet!'
• 'Zip your lip!'
• When repeated, not to be repeated