regurgitation vs reflex action

regurgitation and reflex action both are nouns.

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

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

regurgitation: the reflex act of ejecting the contents of the stomach through the mouth
reflex action: an automatic instinctive unlearned reaction to a stimulus

regurgitation (noun)	reflex action (noun)
the reflex act of ejecting the contents of the stomach through the mouth	an automatic instinctive unlearned reaction to a stimulus
recall after rote memorization
backflow of blood through a defective heart valve