fetid horehound vs Ballota nigra

fetid horehound and Ballota nigra both are nouns.

Word	Noun	Adjective	Verb	Adverb
fetid horehound	Yes	No	No	No
Ballota nigra	Yes	No	No	No

As nouns, fetid horehound and Ballota nigra are synonyms defined as:

fetid horehound and Ballota nigra: ill-smelling European herb with rugose leaves and whorls of dark purple flowers

Other synonyms of fetid horehound include black archangel, black horehound, stinking horehound.

fetid horehound (noun)	Ballota nigra (noun)
ill-smelling European herb with rugose leaves and whorls of dark purple flowers	ill-smelling European herb with rugose leaves and whorls of dark purple flowers