Excoriate, which first appeared in English in the 15th century, comes from "excoriatus," the past participle of the Late Latin verb excoriare, meaning "to strip off the hide." "Excoriare" was itself formed from a pairing of the Latin prefix ex-, meaning "out," and corium, meaning "skin" or "hide" or "leather." "Corium" has several other descendants in English. One is "cuirass," a name for a piece of armor that covers the body from neck to waist (or something, such as bony plates covering an animal, that resembles such armor). Another is "corium" itself, which is sometimes used as a synonym of "dermis" (the inner layer of human skin).