Related Clues:

• Angry teacher's cry
• "Put a sock in it!"
• Peacefully silent
• Director's admonition
• Quell
• "Shh!"
• ''Mum's the word!''
• Without sound
• ''Hush!''
• Muted
• Not talkative
• Restraining order
• Peace partner
• Low in decibels
• Librarian's request