excreta vs barf

excreta and barf both are nouns.

Word	Noun	Adjective	Verb	Adverb
excreta	Yes	No	No	No
barf	Yes	No	Yes	No

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

excreta: waste matter (as urine or sweat but especially feces) discharged from the body
barf: the matter ejected in vomiting

excreta (noun)	barf (noun)
waste matter (as urine or sweat but especially feces) discharged from the body	the matter ejected in vomiting

excreta (verb)	barf (verb)
	eject the contents of the stomach through the mouth