To talk rapidly, incessantly, and on trivial subjects; jabber. To utter a rapid series of short, inarticulate, speechlike sounds: birds chattering in the trees. To click quickly and repeatedly: Our teeth chattered from the cold. To vibrate or rattle while in operation: A power drill will chatter if the bit is loose. To utter in a rapid, usually thoughtless way: chattered a long reply. Idle, trivial talk. Communication, such as e-mail and cell phone calls, between people who are involved in terrorism or espionage, as monitored by a government agency. The sharp, rapid sounds made by some birds and animals. A series of quick rattling or clicking sounds.