Guinea pepper vs negro pepper

Guinea pepper and negro pepper both are nouns.

Word	Noun	Adjective	Verb	Adverb
Guinea pepper	Yes	No	No	No
negro pepper	Yes	No	No	No

As nouns, Guinea pepper and negro pepper are synonyms defined as:

Guinea pepper and negro pepper: tropical west African evergreen tree bearing pungent aromatic seeds used as a condiment and in folk medicine

Other synonyms of Guinea pepper include Xylopia aethiopica.

Guinea pepper (noun)	negro pepper (noun)
tropical west African evergreen tree bearing pungent aromatic seeds used as a condiment and in folk medicine	tropical west African evergreen tree bearing pungent aromatic seeds used as a condiment and in folk medicine
West African plant bearing pungent peppery seeds