vomit vs haematemesis

vomit and haematemesis both are nouns.

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

As nouns, haematemesis is a hyponym of vomit; that is, haematemesis 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
haematemesis: vomiting blood

Other hyponyms of vomit include rumination, hematemesis, hyperemesis.

vomit (noun)	haematemesis (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)	haematemesis (verb)
eject the contents of the stomach through the mouth