Definition of chitin in English:



  • A fibrous substance consisting of polysaccharides and forming the major constituent in the exoskeleton of arthropods and the cell walls of fungi.

    ‘Finally, like other fungi, chytrids have chitin strengthening their cell walls, and one subgroup have cellulose as well, a trait unique among living fungi.’
    • ‘Arthropods have a stiff cuticle made largely of chitin and proteins, forming an exoskeleton that may or may not be further stiffened with calcium carbonate.’
    • ‘There are a few other animal carbohydrates, notably chitin, the substance which constitutes the hard outer casing of insects and crustaceans.’
    • ‘Chitinases are hydrolytic enzymes that catalyze the degradation of chitin, a major component of fungal cell walls.’
    • ‘Despite their obvious differences, both mollusc shells and arthropod cuticle contain chitin.’



/ˈkītn/ /ˈkaɪtn/


Mid 19th century from French chitine, formed irregularly from Greek khitōn (see chiton).