Real Dictionary

papyrus
countable noun: A papyrus is an ancient document that is written on papyrus.
uncountable noun: Papyrus is a tall water plant that grows in Africa.
uncountable noun: Papyrus is a type of paper made from papyrus stems that was used in ancient Egypt, Rome, and Greece.

papyrus in American English
a tall water plant (Cyperus papyrus) of the sedge family, abundant in the Nile region of Egypt and widely cultivated as an ornamental
noun: a tall, aquatic plant, Cyperus papyrus, of the sedge family, native to the Nile valley: the Egyptian subspecies, C. papyrus hadidii, thought to be common in ancient times, now occurs only in several sites

papyrus in British English
noun: a tall aquatic cyperaceous plant, Cyperus papyrus, of S Europe and N and central Africa with small green-stalked flowers arranged like umbrella spokes around the stem top