1) Convert 2) Convert into keratin 3) Keratinise 4) To convert into keratin 5) To make or become keratinous 1) Keratinise 
[v] - convert into keratin 2. [v] - become horny and impregnated with keratin
keratinize To make, or to become, keratinous; to turn into horny tissue.
keratinise verb become horny and impregnated with keratin
to make or become keratinous.