grouse-berry vs grouse whortleberry

grouse-berry and grouse whortleberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
grouse-berry	Yes	No	No	No
grouse whortleberry	Yes	No	No	No

As nouns, grouse-berry and grouse whortleberry are synonyms defined as:

grouse-berry and grouse whortleberry: shrub of northwestern North America bearing red berries

Other synonyms of grouse-berry include grouseberry, Vaccinium scoparium.

grouse-berry (noun)	grouse whortleberry (noun)
shrub of northwestern North America bearing red berries	shrub of northwestern North America bearing red berries