oral fissure vs yap

oral fissure and yap both are nouns.

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

As nouns, yap is a hyponym of oral fissure; that is, yap is a word with a more specific, narrower meaning than oral fissure:

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

Other hyponyms of oral fissure include cakehole, gob, hole, maw, trap.

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

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