puking vs rumination

puking and rumination both are nouns.

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

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

puking: 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 puking include haematemesis, hematemesis, hyperemesis.

puking (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