buckthorn vs shrub

buckthorn and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
buckthorn	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of buckthorn; that is, shrub is a word with a broader meaning than buckthorn:

Other hypernyms of buckthorn include bush.

As nouns, shrub is a hypernym of buckthorn; that is, shrub is a word with a broader meaning than buckthorn:

buckthorn: a shrub or shrubby tree of the genus Rhamnus; fruits are source of yellow dyes or pigments
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of buckthorn include bush.

buckthorn (noun)	shrub (noun)
any shrub or small tree of the genus Bumelia	a low woody perennial plant usually having several major stems
a shrub or shrubby tree of the genus Rhamnus; fruits are source of yellow dyes or pigments
an Old World plantain with long narrow ribbed leaves widely established in temperate regions