chatter

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To talk rapidly, incessantly, and on trivial subjects; jabber.
• intransitive verb To utter a rapid series of short, inarticulate, speechlike sounds.
• intransitive verb To click quickly and repeatedly.
• intransitive verb To vibrate or rattle while in operation.
• intransitive verb To utter in a rapid, usually thoughtless way.
• noun Idle, trivial talk.
• noun Communication, such as e-mail and cell phone calls, between people who are involved in terrorism or espionage, as monitored by a government agency.
• noun The sharp, rapid sounds made by some birds and animals.
• noun A series of quick rattling or clicking sounds.

from The Century Dictionary.

• noun succession of quick, shrill, inarticulate sounds, especially if discordant or jarring, like those uttered by a magpie or a monkey; rapid and imperfectly articulated utterance.
• noun The noise made by the teeth striking together repeatedly and rapidly, as under the influence of cold or fright.
• noun Idle or foolish talk.
• noun Synonyms See prattle, n.
• To utter a succession of quick, shrill, inarticulate sounds, as a magpie or a monkey.
• To make a rapid rattling noise, as the teeth, from cold or fright.
• To talk thoughtlessly, idly, or rapidly; jabber; gabble.
• To argue.
• To jar, so as to form a series of nicks or notches, as a cutting-tool.
• To utter as one who or that which chatters: as, to chatter nonsense.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To utter sounds which somewhat resemble language, but are inarticulate and indistinct.
• intransitive verb To talk idly, carelessly, or with undue rapidity; to jabber; to prate.
• intransitive verb To make a noise by rapid collisions.
• transitive verb To utter rapidly, idly, or indistinctly.
• noun Sounds like those of a magpie or monkey; idle talk; rapid, thoughtless talk; jabber; prattle.
• noun Noise made by collision of the teeth, as in shivering.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun one who chats
• noun Internet a user of chat rooms
• noun talk, especially meaningless or unimportant talk
• noun the sound of talking
• noun the sound made by a magpie
• noun an intermittent noise, as from vibration
• noun in national security, the degree of communication between suspect groups and individuals, used to gauge the degree of expected terrorist activity.
• verb intransitive To talk idly.
• verb intransitive Of teeth, machinery, etc, to make a chattering noise.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb click repeatedly or uncontrollably
• noun noisy talk
• verb cut unevenly with a chattering tool
• verb speak (about unimportant matters) rapidly and incessantly
• verb talk socially without exchanging too much information
• noun the rapid series of noises made by the parts of a machine
• noun the high-pitched continuing noise made by animals (birds or monkeys)
• verb make noise as if chattering away