elderberry bush vs shrub

elderberry bush and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
elderberry bush	Yes	No	No	No
shrub	Yes	No	No	No

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

elderberry bush: any of numerous shrubs or small trees of temperate and subtropical Northern Hemisphere having white flowers and berrylike fruit
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of elderberry bush include bush.

elderberry bush (noun)	shrub (noun)
any of numerous shrubs or small trees of temperate and subtropical Northern Hemisphere having white flowers and berrylike fruit	a low woody perennial plant usually having several major stems