noun

The leaf of an Asian evergreen climbing plant that is used in the East as a mild stimulant. Parings of areca nut, lime, and cinnamon are wrapped in the leaf, which is then chewed, causing the saliva to go red and, with prolonged use, the teeth to go black.

Smoking tobacco, drinking alcohol, and having a poor diet are important risk factors in the West, and chewing betel or areca nuts, smoking bidis, and taking snuff are important in the Indian subcontinent.