Lignin
Pronunciation : Lig"nin
Part of Speech : n.
Etymology : [L. lignum wood: cf. F. lignine.] (Bot.)
Definition : Defn: A substance characterizing wood cells and differing from cellulose in its conduct with certain chemical reagents.
Note: Recent authors have distinguished four forms of this substance, naming them lignose, lignin, lignone, and lignireose.
Source : Webster's Unabridged Dictionary, 1913