Madagascar pepper vs Piper nigrum

Madagascar pepper and Piper nigrum both are nouns.

Word	Noun	Adjective	Verb	Adverb
Madagascar pepper	Yes	No	No	No
Piper nigrum	Yes	No	No	No

As nouns, Madagascar pepper and Piper nigrum are synonyms defined as:

Madagascar pepper and Piper nigrum: climber having dark red berries (peppercorns) when fully ripe; southern India and Sri Lanka; naturalized in northern Burma and Assam

Other synonyms of Madagascar pepper include black pepper, common pepper, pepper, white pepper.

Madagascar pepper (noun)	Piper nigrum (noun)
climber having dark red berries (peppercorns) when fully ripe; southern India and Sri Lanka; naturalized in northern Burma and Assam	climber having dark red berries (peppercorns) when fully ripe; southern India and Sri Lanka; naturalized in northern Burma and Assam