yap away vs rattle on

yap away and rattle on both are verbs.

Word	Noun	Adjective	Verb	Adverb
yap away	No	No	Yes	No
rattle on	No	No	Yes	No

As verbs, yap away and rattle on are synonyms defined as:

Other synonyms of yap away include jaw, yack, yack away.

yap away (verb)	rattle on (verb)
talk incessantly and tiresomely	talk incessantly and tiresomely