Definition of lignin in US English:



  • A complex organic polymer deposited in the cell walls of many plants, making them rigid and woody.

    • ‘Cytochemistry and autofluorescence observations were used to detect the presence of lignin and suberin in unfixed tissues.’
    • ‘Callose, lignin and suberin are polymers that can be elicited as plant defences that reinforce cell walls of some species.’
    • ‘Impregnation of endodermal and hypodermal walls with suberin and lignin should reduce the diameter of interfibrillar spaces.’
    • ‘The hypodermis of all three species has two distinct zones that contain suberin and lignin.’
    • ‘While animal cell membranes decay too rapidly to be pyritised, the cellulose or lignin cell walls of plants are more resistant and may be preserved in this way.’


Early 19th century: from ligni- ‘of wood’ + -in.