keratin

[ ker-uh-tin ]

/ ˈkɛr ə tɪn /

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noun

a fibrous, structural protein that is the principal constituent of hoofs, nails, claws, talons, bills, horn, hair, feathers, etc., and that is found in the outermost layers of skin.

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Origin of keratin

First recorded in 1840–50; kerat- + -in²

Words nearby keratin

Kerala, keramic, keramics, keratalgia, keratectomy, keratin, keratinize, keratinous, keratitis, kerato-, keratoconjunctivitis

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use keratin in a sentence

Light scattering off of microscopic layers of air, the protein keratin and melanin-containing structures called melanosomes creates iridescent feathers’ sheen.
Sunbirds’ dazzling feathers are hot, in both senses of the word|Jake Buehler|August 17, 2021|Science News
Rhino horns are made of keratin, the same protein found in our fingernails.
‘Zoobiquity’: What Animals Can Teach Us About Our Health|Carl Zimmer|June 17, 2012|DAILY BEAST
Keratin is particularly rich in sulphur, and is quite insoluble in cold water.
Principles and Practice of Fur Dressing and Fur Dyeing|William E. Austin
Keratin, a substance forming the chief constituent in the hair, nails, and horn of animals.
The Nuttall Encyclopaedia|Edited by Rev. James Wood

British Dictionary definitions for keratin

keratin

ceratin

/ (ˈkɛrətɪn) /

noun

a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for keratin

keratin

[ kĕr′ə-tĭn ]

Any of a class of tough, fibrous proteins that are the main structural component of hair, nails, horns, feathers, and hooves. Keratins are rich in sulfur-containing amino acids, especially cysteine. Individual keratin molecules are entwined helically around each other in long filaments, which are cross-linked by bonds between sulfur atoms on different chains. The twining and cross-linking produce strength and toughness.