elderberry vs black elder

elderberry and black elder both are nouns.

Word	Noun	Adjective	Verb	Adverb
elderberry	Yes	No	No	No
black elder	Yes	No	No	No

As nouns, elderberry and black elder are synonyms defined as:

elderberry and black elder: a common shrub with black fruit or a small tree of Europe and Asia; fruit used for wines and jellies

Other synonyms of elderberry include bourtree, common elder, European elder, Sambucus nigra.

elderberry (noun)	black elder (noun)
berrylike fruit of an elder used for e.g. wines and jellies	a common shrub with black fruit or a small tree of Europe and Asia; fruit used for wines and jellies
a common shrub with black fruit or a small tree of Europe and Asia; fruit used for wines and jellies