vomit vs hematemesis

vomit and hematemesis both are nouns.

Word	Noun	Adjective	Verb	Adverb
vomit	Yes	No	Yes	No
hematemesis	Yes	No	No	No

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

vomit: the reflex act of ejecting the contents of the stomach through the mouth
hematemesis: vomiting blood

Other hyponyms of vomit include rumination, haematemesis, hyperemesis.

vomit (noun)	hematemesis (noun)
the reflex act of ejecting the contents of the stomach through the mouth	vomiting blood
a medicine that induces nausea and vomiting
the matter ejected in vomiting

vomit (verb)	hematemesis (verb)
eject the contents of the stomach through the mouth