chat·ter / ˈchatər/ • v. [intr.] talk rapidly or incessantly about trivial matters. ∎  (of a bird, monkey, or machine) make a series of quick high-pitched sounds. ∎  (of a person's teeth) click repeatedly together, typically from cold or fear.• n. incessant trivial talk: a stream of idle chatter. ∎  a series of quick high-pitched sounds: the chatter of a typewriter. ∎  undesirable vibration in a mechanism: the wipers should operate without chatter.DERIVATIVES: chat·ter·y adj.

chatter vb. XIII. imit.; see -ER 5.
Hence as sb. XIII. chatterbox XIX.