A random polymer of coniferyl alcohol accompanying cellulose and present in vegetable fiber and wood cells; a source of vanillin (by oxidation of l.); l. composition varies with plant species. It is one of the most abundant biopolymers in nature. [L. lignum, wood]
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lig·nin 'lig-nən n an amorphous polymeric substance related to cellulose that together with cellulose forms the woody cell walls of plants and the cementing material between them
Medical dictionary. 2011.