buckthorn berry vs fruit

buckthorn berry and fruit both are nouns.

Word	Noun	Adjective	Verb	Adverb
buckthorn berry	Yes	No	No	No
fruit	Yes	No	Yes	No

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

buckthorn berry (noun)	fruit (noun)
fruit of various buckthorns yielding dyes or pigments	an amount of a product
	the consequence of some effort or action
	the ripened reproductive body of a seed plant

buckthorn berry (verb)	fruit (verb)
	bear fruit
	cause to bear fruit