seed vessel vs bur

seed vessel and bur both are nouns.

Word	Noun	Adjective	Verb	Adverb
seed vessel	Yes	No	No	No
bur	Yes	No	Yes	No

As nouns, bur is a hyponym of seed vessel; that is, bur is a word with a more specific, narrower meaning than seed vessel:

Other hyponyms of seed vessel include epicarp, exocarp, mesocarp, endocarp, pit, stone, capsule, burr.

seed vessel (noun)	bur (noun)
the ripened and variously modified walls of a plant ovary	small bit used in dentistry or surgery
	seed vessel having hooks or prickles

seed vessel (verb)	bur (verb)
	remove the burrs from