0 having changed into, or changed so as to contain, keratin (= the main substance that forms hair, nails, horns, feathers, etc.) :
The deeper cell layers of the epidermis proliferate, with the cells gradually passing towards the surface and becoming keratinized as they do so.
The fungus has been found inside the keratinized cells of the epidermis of adult or newly metamorphosed animals.
The seal's eye is protected on land and underwater by the strongly keratinized corneal epithelium.
