betel pepper vs Piper betel

betel pepper and Piper betel both are nouns.

Word	Noun	Adjective	Verb	Adverb
betel pepper	Yes	No	No	No
Piper betel	Yes	No	No	No

As nouns, betel pepper and Piper betel are synonyms defined as:

betel pepper and Piper betel: Asian pepper plant whose leaves are chewed with betel nut (seed of the betel palm) by southeast Asians

Other synonyms of betel pepper include betel.

betel pepper (noun)	Piper betel (noun)
Asian pepper plant whose leaves are chewed with betel nut (seed of the betel palm) by southeast Asians	Asian pepper plant whose leaves are chewed with betel nut (seed of the betel palm) by southeast Asians