bittersweet nightshade vs deadly nightshade

bittersweet nightshade and deadly nightshade both are nouns.

Word	Noun	Adjective	Verb	Adverb
bittersweet nightshade	Yes	No	No	No
deadly nightshade	Yes	No	No	No

As nouns, bittersweet nightshade and deadly nightshade are synonyms defined as:

bittersweet nightshade and deadly nightshade: poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America

Other synonyms of bittersweet nightshade include bittersweet, climbing nightshade, poisonous nightshade, Solanum dulcamara, woody nightshade.

bittersweet nightshade (noun)	deadly nightshade (noun)
poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America	poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America
	perennial Eurasian herb with reddish bell-shaped flowers and shining black berries; extensively grown in United States; roots and leaves yield atropine