emesis vs rumination

emesis and rumination both are nouns.

Word	Noun	Adjective	Verb	Adverb
emesis	Yes	No	No	No
rumination	Yes	No	No	No

As nouns, rumination is a hyponym of emesis; that is, rumination is a word with a more specific, narrower meaning than emesis:

emesis: the reflex act of ejecting the contents of the stomach through the mouth
rumination: regurgitation of small amounts of food; seen in some infants after feeding

Other hyponyms of emesis include haematemesis, hematemesis, hyperemesis.

emesis (noun)	rumination (noun)
the reflex act of ejecting the contents of the stomach through the mouth	regurgitation of small amounts of food; seen in some infants after feeding
	(of ruminants) chewing (the cud)
	a calm, lengthy, intent consideration