yawn vs unconditioned reflex

yawn and unconditioned reflex both are nouns.

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

As nouns, unconditioned reflex is a hypernym of yawn; that is, unconditioned 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
unconditioned reflex: an automatic instinctive unlearned reaction to a stimulus

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