yak vs prattle

yak and prattle both are nouns.

Word	Noun	Adjective	Verb	Adverb
yak	Yes	No	Yes	No
prattle	Yes	No	Yes	No

As nouns, prattle is a hyponym of yak; that is, prattle is a word with a more specific, narrower meaning than yak:

Other hyponyms of yak include blether, chin music, idle talk, prate.

yak (noun)	prattle (noun)
large long-haired wild ox of Tibet often domesticated	idle or foolish and irrelevant talk
noisy talk

yak (verb)	prattle (verb)
talk profusely	speak (about unimportant matters) rapidly and incessantly