yawn vs inborn reflex

yawn and inborn reflex both are nouns.

Word	Noun	Adjective	Verb	Adverb
yawn	Yes	No	Yes	No
inborn reflex	Yes	No	No	No

As nouns, inborn reflex is a hypernym of yawn; that is, inborn reflex is a word with a broader meaning than yawn:

yawn: an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom
inborn reflex: an automatic instinctive unlearned reaction to a stimulus

yawn (noun)	inborn reflex (noun)
an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom	an automatic instinctive unlearned reaction to a stimulus

yawn (verb)	inborn reflex (verb)
utter a yawn, as from lack of oxygen or when one is tired
be wide open