After the nonmedical use of the term epidemic by Homer, Sophocles, Plato, and Xenophon, Hippocrates gave it its medical meaning. However, the term has since undergone a long evolution. The adjective epidemios gave rise to the Greek noun epidemia. The Greek term epidemia in turn gave rise to the Latin term epidimia or epidemia. The term ypidime in Medieval French has its origins in these Latin words and went on to become épydime in the 14th century, epidimie in the 17th century, and then epidémie in the 18th century. Not until 22 centuries after Hippocrates, in the second half of the 19th century, were the terms épidémiologie (1855), épidémiologique (1878), and épidémiologiste (1896) coined in French and notions attached to them developed. Of course, at approximately the same time, corresponding terms appeared in the English language. The term epidemic and the terms linked to it therefore required an extremely long time to be constructed. This evolution is representative of the evolution of science and medicine over the centuries and reflects the semantic evolution of the term.