eructation vs reflex response

eructation and reflex response both are nouns.

Word	Noun	Adjective	Verb	Adverb
eructation	Yes	No	No	No
reflex response	Yes	No	No	No

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

eructation: a reflex that expels gas noisily from the stomach through the mouth
reflex response: an automatic instinctive unlearned reaction to a stimulus

eructation (noun)	reflex response (noun)
a reflex that expels gas noisily from the stomach through the mouth	an automatic instinctive unlearned reaction to a stimulus
(of volcanoes) pouring out fumes or lava (or a deposit so formed)