Definition of mumble

• v. - 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.
• v. - To chew something gently with closed lips.
• v. t. - To utter with a low, inarticulate voice.
• v. t. - To chew or bite gently, as one without teeth.
• v. t. - To suppress, or utter imperfectly.