The Collaborative International Dictionary of English v.0.48:

Gabble \Gab"ble\, v. i. [imp. & p. p. Gabbled; p. pr. & vb. n.
   Gabbling.] [Freq. of gab. See Gab, v. i.]
   1. To talk fast, or to talk without meaning; to prate; to
      jabber. --Shak.
      [1913 Webster]

   2. To utter inarticulate sounds with rapidity; -- used of
      fowls as well as people; as, gabbling geese.
      [1913 Webster +PJC]