blue elder vs blue elderberry

blue elder and blue elderberry both are nouns.

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

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

blue elder and blue elderberry: shrub or small tree of western United States having white flowers and blue berries; fruit used in wines and jellies

Other synonyms of blue elder include Sambucus caerulea.

blue elder (noun)	blue elderberry (noun)
shrub or small tree of western United States having white flowers and blue berries; fruit used in wines and jellies	shrub or small tree of western United States having white flowers and blue berries; fruit used in wines and jellies