bone-ash cup vs vessel

bone-ash cup and vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
bone-ash cup	Yes	No	No	No
vessel	Yes	No	No	No

As nouns, vessel is a hypernym of bone-ash cup; that is, vessel is a word with a broader meaning than bone-ash cup:

bone-ash cup: a small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead
vessel: an object used as a container (especially for liquids)

bone-ash cup (noun)	vessel (noun)
a small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead	a craft designed for water transportation
	an object used as a container (especially for liquids)
	a tube in which a body fluid circulates