Related Clues:

• Complains sotto voce
• Grumps
• Grumbles
• One makes it low-down, in a manner of speaking
• This loses its head and speaks in a low sort of way
• How grand when one speaks in such a low way!
• Grumbles quietly
• 'Trust me!' comic says none too clearly
• Says 'You no-good son of a ...,' say
• Grumbles sotto voce