chitin

From French chitine, from Latin chitōn (“mollusk”), from Ancient Greek χιτών (khitṓn). See also chiton.

• enPR: kīʹtĭn, IPA^(key): /ˈkaɪtɪn/

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• Rhymes: -aɪtɪn

chitin (countable and uncountable, plural chitins)

1. (biochemistry) A complex polysaccharide, a polymer of N-acetylglucosamine, found in the exoskeletons of arthropods and in the cell walls of fungi; thought to be responsible for some forms of asthma in humans.
   • 1880, Arthur Gamgee, A Text-book of the Physiological Chemistry of the Animal Body‎, Macmillan, page 299:

     Chitin usually occurs throughout Invertebrates in the form of an investment to the outermost cellular layer or ectoderm.

   • 2004 September 11, New Scientist, page 19:

     The robot’s energy source is the sugar in the polysaccharide called chitin that makes up a fly’s exoskeleton.

• “chitin”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• Douglas Harper (2001–2024) “chitin”, in Online Etymology Dictionary.

• itchin'