sunberry vs poison-berry

sunberry and poison-berry both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunberry	Yes	No	No	No
poison-berry	Yes	No	No	No

As nouns, poison-berry is a hypernym of sunberry; that is, poison-berry is a word with a broader meaning than sunberry:

sunberry: improved garden variety of black nightshade having small edible orange or black berries
poison-berry: Eurasian herb naturalized in America having white flowers and poisonous hairy foliage and bearing black berries that are sometimes poisonous but sometimes edible

Other hypernyms of sunberry include black nightshade, common nightshade, poisonberry, Solanum nigrum.

sunberry (noun)	poison-berry (noun)
improved garden variety of black nightshade having small edible orange or black berries	Eurasian herb naturalized in America having white flowers and poisonous hairy foliage and bearing black berries that are sometimes poisonous but sometimes edible