betel, also called paan, pinang, or penang, either of two different plants whose leaves and seeds are used in combination for chewing purposes throughout wide areas of southern Asia and the East Indies. The betel nut is the seed of the areca, or betel, palm (Areca catechu), family Arecaceae, and the betel leaf is from the betel pepper, or pan plant (Piper betle), family Piperaceae. Betel chewing is a habit of an estimated one-tenth of the world’s population, and betel is the fourth most common psychoactive drug in the world, following nicotine, alcohol, and caffeine.