mumble /ˈmʌmbəl/verb 2noun 1forms 5 verb2 •To speak unintelligibly or inaudibly; to fail to articulate.Please try not to mumble so I can hear you better. •To chew something gently with closed lips. noun1 •A quiet or unintelligible vocalization; a low tone of voice.All I could hear was a mumble from the next room.He spoke in a barely comprehensible mumble. formsmumbled · mumbling · mumbles · mumbleth · mumblest