rhizoverbBeta
DictionarykeratinStructural protein
noun

keratin

KAIR-uh-tin/ˈkerətɪn/

A tough protein that forms hair, nails, and the outer layer of skin.

The vial contains keratin, the tough protein found in the feather beside it.

Depict keratin as an isolated laboratory protein, rather than treating its host tissues as the protein itself.
Etymology
keratGreekhorn
+inEnglishchemical substance

The name identifies keratin as a substance of horn. That connection extends to hair, nails, and feathers, which contain the same tough structural protein.

In context

Animals world0:45
Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws.
What do you know about Turtle: A documentary about the life of Turtle

More examples

  • The outer layer of your skin contains keratin.
  • Birds have keratin in their feathers and beaks.
  • A hair strand consists mostly of keratin.

Forms

keratinous adjective — Made of or containing tough keratin.