common elder vs elderberry

common elder and elderberry both are nouns.

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

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

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

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

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