mumble āļāļ·āļāļāļ°āđāļĢ mumble āļāļ·āļāļāļ°āđāļĢ To utter indistinctly by lowering the voice or partially closing the mouth: mumbled an insincere apology. To chew slowly or ineffectively without or as if without teeth.To speak words indistinctly, as by lowering the voice or partially closing the mouth.To chew food slowly or ineffectively, as if with the gums.A low indistinct sound or utterance.