sciatherics
/sʌɪəˈθɛrɪks/(also sciaterics, skiatherics)
noun
The use or interpretation of shadows cast by the sun, especially to tell the time of day; the art of dialling.
Origin
Mid 17th century; earliest use found in John Gregory (1607–1646), orientalist. From post-classical Latin sciotericus, sciathericus, sciothericus: see -ic.