Related Clues:

• Kind of understanding
• Mother
• Idiotic
• Remote choice
• Suggested
• Much like Marcel Marceau
• Unvoiced
• Unthinking
• Trumpeter's muffler
• Sordino, e.g.
• 'Put a sock in it!'
• Angry teacher's cry
• Not saying much
• "Put a sock in it!"
• Peacefully silent