chatter vs yack

chatter and yack both are nouns.

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

As nouns, chatter and yack are synonyms defined as:

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

chatter (noun)	yack (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

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