Source : Webster's Revised Unabridged Dictionary (1913)

Papyrus \Pa*py"rus\, n.; pl. {Papyri}. [L., fr. Gr. ?. See
   {Paper}.]
   1. (Bot.) 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.

   2. 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.

   3. A manuscript written on papyrus; esp., pl., written
      scrolls made of papyrus; as, the papyri of Egypt or
      Herculaneum.

Source : WordNet®

papyrus
     n 1: paper made from the papyrus plant by cutting it in strips
          and pressing it flat; used by ancient Egyptians and
          Greeks and Romans
     2: tall sedge of the Nile valley yielding fiber that served
        many purposes in historic times [syn: {Egyptian paper reed},
         {Egyptian paper rush}, {paper rush}, {paper plant}, {Cyperus
        papyrus}]
     3: a document written on papyrus
     [also: {papyri} (pl)]