a tall rushlike plant (cyperus papyrus) of the sedge family, formerly growing in egypt, and now found in abyssinia, syria, sicily, etc. the stem is triangular and about an inch thick.-the material upon which the ancient egyptians wrote. it was formed by cutting the stem of the plant into thin longitudinal slices, which were gummed together and pressed.-a manuscript written on papyrus; esp., pl., written scrolls made of papyrus; as, the papyri of egypt or herculaneum.