noun pl. papyri -·ri′ (-rī′) or papyruses -·ruses

1. a tall water plant (Cyperus papyrus) of the sedge family, abundant in the Nile region of Egypt and widely cultivated as an ornamental
2. a writing material made from this plant by the ancient Egyptians, Greeks, and Romans, by soaking, pressing, and drying thin slices of its pith laid crosswise
3. any ancient document or manuscript on papyrus

Etymology: ME papirus < L papyrus < Gr papyros, prob. < Coptic paparo < ? Egypt pʾ-n-pr-ʿʾ, that of the pharaoh