oscitancy vs reflex action

oscitancy and reflex action both are nouns.

Word	Noun	Adjective	Verb	Adverb
oscitancy	Yes	No	No	No
reflex action	Yes	No	No	No

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

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

oscitancy (noun)	reflex action (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
drowsiness and dullness manifested by yawning