Keratin is a fibrous protein that forms the primary structural component of hair, nails, and skin. While it is a crucial protein for these parts of the body, there are many synonyms for keratin. Some of the most common synonyms include the following: scleroprotein, horn protein, and hooves protein. Other synonyms include medullin, trichocysts, and epidermin. Additionally, there are several related terms, such as keratocytes (the cells that produce keratin) and keratinization, which refers to the process of forming keratin. With its vital role in various bodily structures and functions, it's important to understand the different terms that refer to keratin.