Piper betel vs betel pepper

Piper betel and betel pepper both are nouns.

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

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

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

Other synonyms of Piper betel include betel.

Piper betel (noun)	betel pepper (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