1. The high-pitched continuing noise made by animals (birds or monkeys); SYN. chattering.
2. The rapid series of noises made by the parts of a machine; SYN. chattering.

1. To speak (about unimportant matters) rapidly and incessantly; SYN. piffle, palaver, prate, tittle-tattle, twaddle, clack, maunder, prattle, gibber, tattle, blabber, gabble.
2. To make noise as if chattering away.
3. To click repeatedly or uncontrollably, as of teeth; SYN. click.
4. To cut unevenly with a chattering tool.

The rapid cycling on and off of a relay in a control process due to insufficient bandwidth in the controller.