(1):

(v. i.) To talk rapidly, indistinctly, or unintelligibly; to utter gibberish or nonsense; to chatter.

(2):

(n.) Rapid or incoherent talk, with indistinct utterance; gibberish.

(3):

(v. t.) To utter rapidly or indistinctly; to gabble; as, to jabber French.

(4):

(n.) One who jabbers.