barf vs excrement

barf and excrement both are nouns.

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

As nouns, excrement is a hypernym of barf; that is, excrement is a word with a broader meaning than barf:

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

Other hypernyms of barf include body waste, excreta, excretion, excretory product.

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

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