mutter
🇺🇸
/ˈmʌtər/
🇬🇧
/ˈmʌtə(r)/
to speak quietly in a low voice that is hard to hear, often when annoyed
He would mutter complaints under his breath when he was upset.
to complain quietly without saying it openly
People often mutter about the weather when it rains.
a quiet sound or words that are hard to hear
I heard a soft mutter from the next room.