semeiology
Se`mei*ol"o*gy, or Se`mi*ol"o*gy, n. Etym: [Gr. shmei^on a mark, a sign + -logy.] Defn: The science or art of signs. Specifically: (a) (Med.) The science of the signs or symptoms of disease; symptomatology. (b) The art of using signs in signaling.