Definition of "mumble"

mumble

/ˈmʌmbəl/

verb
third-person singular simple present mumbles, present participle mumbling, simple past and past participle mumbled
1. (transitive, intransitive) To speak unintelligibly or inaudibly; to fail to articulate.
  Quotations
  Peace, you mumbling fool.
  c. 1591–1595 (date written), William Shakespeare, “The Tragedie of Romeo and Ivliet”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene v]
  A wrinkled hag, with age grown double, / Picking dry sticks, and mumbling to herself.
  1680, Thomas Otway, The Orphan
2. To chew something gently with closed lips.
noun
plural mumbles
1. A quiet or unintelligible vocalization; a low tone of voice.