vomit up vs purge

vomit up is not a noun while purge is a noun.

Word	Noun	Adjective	Verb	Adverb
vomit up	No	No	Yes	No
purge	Yes	No	Yes	No

As verbs, vomit up and purge are synonyms defined as:

Other synonyms of vomit up include barf, be sick, cast, cat, chuck, disgorge, honk, puke, regorge, regurgitate, retch, sick, spew, spue, throw up, upchuck, vomit.

vomit up (noun)	purge (noun)
	an act of removing by cleansing; ridding of sediment or other undesired elements
	the act of clearing yourself (or another) from some stigma or charge
	an abrupt or sudden removal of a person or group from an organization or place

vomit up (verb)	purge (verb)
eject the contents of the stomach through the mouth	excrete or evacuate (someone's bowels or body)
	eject the contents of the stomach through the mouth
	rid of impurities
	rinse, clean, or empty with a liquid
	make pure or free from sin or guilt
	clear of a charge
	oust politically