Definitions:

1. Speaking or saying something rapidly, incoherently, and without making sense. VERB
   • She rushed into the room jabbering something about a dog.
2. To utter a rapid succession of unintelligible sounds, generally more noisy than chattering. VERB
   • I had to listen to him jabbering endlessly about his new girlfriend.

Synonyms:

• Babbling
• chattering
• driveling
• gabbling
• prattling