All muttered synonyms

adjective muttered

• mumbled — Simple past tense and past participle of mumble.
• murmured — a low, continuous sound, as of a brook, the wind, or trees, or of low, indistinct voices.
• muffled — to wrap with something to deaden or prevent sound: to muffle drums.
• inaudible — not audible; incapable of being heard.
• slurred — to pass over lightly or without due mention or consideration (often followed by over): The report slurred over her contribution to the enterprise.
• low — to utter by or as by lowing.
• incomprehensible — impossible to understand or comprehend; unintelligible.
• unintelligible — not intelligible; not capable of being understood.
• incoherent — without logical or meaningful connection; disjointed; rambling: an incoherent sentence.
• faint — lacking brightness, vividness, clearness, loudness, strength, etc.: a faint light; a faint color; a faint sound.
• inarticulate — lacking the ability to express oneself, especially in clear and effective speech: an inarticulate public speaker.
• garbled — to confuse unintentionally or ignorantly; jumble: to garble instructions.