Definitions for betel nut
Random House Webster's College Dictionary
the astringent kernel of the seed of the betel palm, chewed in many tropical regions in combination with slaked lime and the leaves of the betel plant.
Origin of betel nut:
betel nut, areca nut(noun)
seed of betel palm; chewed with leaves of the betel pepper and lime as a digestive stimulant and narcotic in southeastern Asia
An egg-shaped seed of the betel palm; wrapped in the leaves of the betel pepper and chewed.
the nutlike seed of the areca palm, chewed in the East with betel leaves (whence its name) and shell lime