Related Clues:

• 'Don't let them hear us!'
• License (anag)
• "Stop your yakking!"
• Volume control?
• 'Stop talking!'
• Hush!
• "Too noisy!"
• "Hush"
• Audible silencer
• Peremptory signal
• Quiet "Quiet!"
• ''Put a sock in it!''
• "That's enough from you!"
• Warning that often precedes 17-, 30-, 49- and 65-Across
• Quiet please