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

These fungal tubes are made of rigid cells that contain chitin, the same compound found in insect exoskeletons. — Quanta Magazine, 6 Apr. 2026

In nature, scales of chitin (a polysaccharide common to insects), for example, are arranged like roof tiles. — ArsTechnica, 18 Feb. 2026

The beak — also called the jaw — is the only rigid portion, made of chitin, a tough material also found in the shells of crabs, lobsters and insects. — Ryan Brennan, Miami Herald, 24 Apr. 2026

Fungi fossils preserved in the chert contained compounds from the breakdown of chitin and glucan, key structural molecules in fungi. — Katie Hunt, CNN Money, 5 Feb. 2026

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