oscitance vs instinctive reflex

oscitance and instinctive reflex both are nouns.

Word	Noun	Adjective	Verb	Adverb
oscitance	Yes	No	No	No
instinctive reflex	Yes	No	No	No

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

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

oscitance (noun)	instinctive 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
drowsiness and dullness manifested by yawning