paper plant pa·perp·lant uncommon noun 1. tall sedge of the Nile valley yielding fiber that served many purposes in historic times SynonymspapyrusEgyptian paper reedEgyptian paper rushpaper rushpaper plantCyperus papyrus Related words Broader terms sedge Parts Cyperus WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.