yap vs oral fissure

yap and oral fissure both are nouns.

Word	Noun	Adjective	Verb	Adverb
yap	Yes	No	Yes	No
oral fissure	Yes	No	No	No

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

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

Other hypernyms of yap include mouth, oral cavity, rima oris.

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

yap (verb)	oral fissure (verb)
bark in a high-pitched tone