chitin

noun

chi·​tin ˈkī-tᵊn 

: a horny polysaccharide (C₈H₁₃NO₅)_n that forms part of the hard outer integument especially of insects, arachnids, and crustaceans

chitinous

ˈkī-tᵊn-əs 

ˈkīt-nəs

adjective

Examples of chitin in a Sentence

Recent Examples on the Web

Plus, the researchers detected no chemical trace of chitin, a polymer found in the cell walls of all living fungi and in the fossil fungi that were preserved alongside Prototaxites. —Cody Cottier, Scientific American, 21 Jan. 2026

Because chitin can be sourced from seafood waste and fungal biomass, the approach offers a pathway to turn biological byproducts into high-value energy materials. —Neetika Walter, Interesting Engineering, 31 Dec. 2025

Their bodies are made up of calcium carbonate and chitin, the same material that forms crab shells. —Laura Baisas Aug 20, Popular Science, 20 Aug. 2025

The scales of chitin (a polysaccharide common to insects) in butterfly wings, for example, are arranged like roof tiles. —Jennifer Ouellette, ArsTechnica, 30 July 2025

Word History

Etymology

French chitine, from Greek chitōn

First Known Use

circa 1839, in the meaning defined above

Rhymes for chitin

• brighten
• frighten
• heighten
• lighten
• phaeton
• tighten
• titan
• triton
• whiten
• enlighten
• exciton
• periphyton

Kids Definition

chitin

noun

chi·​tin ˈkīt-ᵊn 

: a horny substance that forms part of the hard outer body covering especially of insects and crustaceans

chitinous

ˈkīt-ᵊn-əs 

ˈkīt-nəs

adjective

Medical Definition

chitin

noun

chi·​tin ˈkīt-ᵊn 

: a horny polysaccharide that forms part of the hard outer integument especially of insects, arachnids, and crustaceans

chitinous

ˈkīt-ᵊn-əs, ˈkīt-nəs 

adjective