keratinized

adj. (Biology) transformed into a horny substance, having acquired a horny texture (also keratinised)

v. Biology) become horny, become horn-like, convert into keratin (also keratinise)

Epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the body's surface and is made up of stratified squamous epithelium with an underlying basal lamina.
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Verb
1. convert into keratin
(synonym) keratinise
(hypernym) convert
(verb-group) keratinise
2. become horny and impregnated with keratin
(synonym) keratinise
(hypernym) change
(verb-group) keratinise
(derivation) keratinization, keratinisation