yack vs chatter

yack and chatter both are nouns.

Word	Noun	Adjective	Verb	Adverb
yack	Yes	No	Yes	No
chatter	Yes	No	Yes	No

As nouns, yack and chatter are synonyms defined as:

Other synonyms of yack include cackle, yak, yakety-yak.

yack (noun)	chatter (noun)
noisy talk	noisy talk
	the high-pitched continuing noise made by animals (birds or monkeys)
	the rapid series of noises made by the parts of a machine

yack (verb)	chatter (verb)
talk incessantly and tiresomely	speak (about unimportant matters) rapidly and incessantly
	talk socially without exchanging too much information
	make noise as if chattering away
	cut unevenly with a chattering tool
	click repeatedly or uncontrollably