The Collaborative International Dictionary of English v.0.48:

Babble \Bab"ble\ (b[a^]b"b'l), v. i. [imp. & p. p. Babbled
   (b[a^]b"b'ld); p. pr. & vb. n. Babbling.] [Cf. LG. babbeln,
   D. babbelen, G. bappeln, bappern, F. babiller, It. babbolare;
   prob. orig., to keep saying ba, imitative of a child learning
   to talk.]
   1. To utter words indistinctly or unintelligibly; to utter
      inarticulate sounds; as a child babbles.
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   2. To talk incoherently; to utter unmeaning words.
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   3. To talk much; to chatter; to prate.
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   4. To make a continuous murmuring noise, as shallow water
      running over stones.
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            In every babbling brook he finds a friend.
                                                  --Wordsworth.
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   Note: Hounds are said to babble, or to be babbling, when they
         are too noisy after having found a good scent.
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   Syn: To prate; prattle; chatter; gossip.
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The Collaborative International Dictionary of English v.0.48:

Babble \Bab"ble\, v. t.
   1. To utter in an indistinct or incoherent way; to repeat, as
      words, in a childish way without understanding.
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            These [words] he used to babble in all companies.
                                                  --Arbuthnot.
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   2. To disclose by too free talk, as a secret.
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The Collaborative International Dictionary of English v.0.48:

Babble \Bab"ble\, n.
   1. Idle talk; senseless prattle; gabble; twaddle. "This is
      mere moral babble." --Milton.
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   2. Inarticulate speech; constant or confused murmur.
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            The babble of our young children.     --Darwin.
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            The babble of the stream.             --Tennyson.
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WordNet (r) 3.0 (2006):

babble
    n 1: gibberish resembling the sounds of a baby [syn: babble,
         babbling, lallation]
    v 1: utter meaningless sounds, like a baby, or utter in an
         incoherent way; "The old man is only babbling--don't pay
         attention"
    2: to talk foolishly; "The two women babbled and crooned at the
       baby" [syn: babble, blather, smatter, blether,
       blither]
    3: flow in an irregular current with a bubbling noise; "babbling
       brooks" [syn: ripple, babble, guggle, burble,
       bubble, gurgle]
    4: divulge confidential information or secrets; "Be careful--his
       secretary talks" [syn: spill the beans, let the cat out of
       the bag, talk, tattle, blab, peach, babble,
       sing, babble out, blab out] [ant: keep one's mouth
       shut, keep quiet, shut one's mouth]