belching vs reflex response

belching and reflex response both are nouns.

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

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

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

belching (noun)	reflex response (noun)
a reflex that expels gas noisily from the stomach through the mouth	an automatic instinctive unlearned reaction to a stimulus
the forceful expulsion of something from inside