'Lignin' definitions:

Definition of 'lignin'

From: WordNet
noun
A complex polymer; the chief constituent of wood other than carbohydrates; binds to cellulose fibers to harden and strengthen cell walls of plants

Definition of 'Lignin'

From: GCIDE
  • Lignin \Lig"nin\ (l[i^]g"n[i^]n), n. [L. lignum wood: cf. F. lignine.] (Bot.) A substance characterizing wood cells and differing from cellulose in its conduct with certain chemical reagents. [1913 Webster]
  • Note: Recent authors have distinguished four forms of this substance, naming them lignose, lignin, lignone, and lignireose. [1913 Webster]