yap vs rima oris

yap and rima oris both are nouns.

Word	Noun	Adjective	Verb	Adverb
yap	Yes	No	Yes	No
rima oris	Yes	No	No	No

As nouns, rima oris is a hypernym of yap; that is, rima oris is a word with a broader meaning than yap:

yap: informal terms for the mouth
rima oris: the opening through which food is taken in and vocalizations emerge

Other hypernyms of yap include mouth, oral cavity, oral fissure.

yap (noun)	rima oris (noun)
informal terms for the mouth	the opening through which food is taken in and vocalizations emerge

yap (verb)	rima oris (verb)
bark in a high-pitched tone