Webster’s Revised Unabridged Dictionary · 1913
Lignification
Lig′ni·fi·ca′tion (lĭg′nĭ·fĭ·kā′shŭn), n. [Cf. F. lignification. See Lignify.] (Bot.) A change in the character of a cell wall, by which it becomes harder. It is supposed to be due to an incrustation of lignin.