babble
bab·ble
I
 /ˈbæbəl/  verb  , bab·bles, bab·bled, bab·bling [  no obj  ]
  1 a : to talk foolishly or too much
   Pay no attention to her. She's just babbling.
   He'll babble on about sports all night if you let him.
   a babbling idiot
  1 b : to make speech sounds that do not make sense to the hearer
   Her cousins were babbling in an unfamiliar dialect.
   The baby babbled happily.
  2 : to make the quiet sound of water flowing over rocks
   a babbling brook
  bab·bler /ˈbæbəɬɚ/  noun  ,  pl   bab·blers [  count  ]
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II
  noun   [  noncount  ]
  1 a : the confusing sound of many people speaking at the same time
   a babble of voices
  1 b : talk that is silly or pointless
   listening to their constant babble
  2 : a quiet sound made by flowing water
   the babble of a brook