| mumble(noun, verb, go, deliver, low) |
| murmur(noun, verb, expression, go, sound) |
| whisper(noun, verb, go, information, express) |
| grumble(noun, verb, low, happy, protest) |
| maunder(verb, wander, lamentation, mumble) |
| croak(verb, grumble, lamentation, mumble, stammering) |
| groan(verb, protest, complain, voice, grumble) |
| growl(verb, utter, grumble, babble, whisper) |
| grunt(noun, verb, low, happy, complain) |
| murmuration(noun, low, buzz, vocalization, monotone) |
| muttering(noun, verb, low, buzz) |
| complain(verb, protest, roar, grumble, moan) |
| moan(verb, protest, complain, utter, flow) |
| murmuring |
| grouch(verb, protest, complain, grumble, nag) |
| gnarl(verb, threat) |
| grouse(verb, protest, complain, grumble, moan) |
| mussitate |
| rumble(noun, verb, utter, buzz, grumble) |
| snarl(verb, grumble, threat, mumble) |