Keratin
/ˈkɛr.ə.tɪn/noun
A fibrous protein forming the main structural constituent of hair, nails, and the outer layer of skin.
Did you know?The word 'keratin' comes from the Greek word for 'horn', linking it to the stronger, protective qualities of horns and hooves in ancient animals.
Etymological Timeline
Ancient Greek
Greek
kerat-
“horn”
Latin
Latin
keratinus
“horn-like, pertaining to horns”
16th Century
Latin
keratina
“a substance derived from horns or hooves”
Modern English
English
keratin
“a structural protein found in hair, nails, and skin”