Difference between Mutter and Mumble

MUTTER vs MUMBLE: NOUN

Repressed or obscure utterance.
Peas
A low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
A repressed or obscure utterance; an instance of muttering.
A murmur or murmuring; sullen or veiled utterance.
A low grumble or indistinct utterance.
A complaint uttered in a low and indistinct tone

To make a sound with a low, rumbling noise.
To utter words, especially complaints or angry expressions, indistinctly or with a low voice and lips partly closed; to say under one's breath.
Talk indistinctly; usually in a low voice
Make complaining remarks or noises under one's breath
To speak softly and incoherently, or with imperfect articulations.

To utter or say in low indistinct tones.
To complain or grumble morosely.
To speak indistinctly in low tones.
To utter words indistinctly or with a low voice and lips partly closed; esp., to utter indistinct complaints or angry expressions; to grumble; to growl.
To sound with a low, rumbling noise.

To suppress, or utter imperfectly.
To chew or bite gently, as one without teeth.
To chew something gently with closed lips.
To speak with the lips partly closed, so as to render the sounds inarticulate and imperfect; to utter words in a grumbling indistinct manner, indicating discontent or displeasure; to mutter.
To utter with a low, inarticulate voice.

A low continuous indistinct sound
Talk indistinctly
Usually in a low voice
To utter with imperfect articulation, or in a low murmuring tone.
To emit a low rumbling sound.
To utter words in a low tone and with compressed lips, as in complaint or sullenness; murmur; grumble.

To speak with the vocal organs partly closed, so as to render the sounds inarticulate and imperfect; speak in low tones, hesitatingly, or deprecatingly.
To chew or bite softly or with the gums; work food with the gums on account of lack or defectiveness of teeth.
To utter in a low inarticulate voice.
To chew gently; work (food) by rubbing it with the gums on account of lack of teeth.
Grind with the gums
Usually in a low voice
Talk indistinctly
To cover up or hide, as if by uttering in a mumbling, unintelligible fashion; say over inarticulately: with up.

Snigger, Exclaim, Groan, Moan, Mussitate, Murmuration, Maffle, Maunder, Gnarl, Croak, Grumbling, Murmur, Grumble, Murmuring, Mumble

Unintelligible, Gibberish, Groan, Incoherently, Unintelligibly, Whisper, Blurt, Inaudibly, Peg, Slur, Maffle, Mussitate, Maunder, Gum, Mutter

Sotto voce, Yell, Shout, Blurt, Snigger, Exclaim, Groan, Moan, Maffle, Gnarl, Grumbling, Murmur, Grumble, Murmuring, Mumble

Gurgle, Sob, Inarticulate, Yell, Sotto voce, Unintelligible, Gibberish, Groan, Unintelligibly, Whisper, Blurt, Inaudibly, Slur, Maffle, Mutter

Mumble Rap: cultural laziness or a true reflection of contemporary times?
Ask first if he knows what it means to mumble.
The teller should not mumble or be difficult to hear.
The bar spotted with regulars who mumble hello to him.
All The Mumble About kreeg hierdoor de nodige attentie waarde.
If that happens, the debate will be mumble jumbled.
Speak with him and he will mumble about Yarrow.
Attempts to kill and eat Mumble great thing.
You soon learn to mumble with great incoherence.
After installation, you should have a new Mumble folder in your Start Menu, from which you can start Mumble.