Forum name:why is it sina?

Sinae

Sinae was an ancient Greek and Roman name for some people who dwelt south of the Seres in the eastern extremity of the inhabitable world. References to the Sinae include mention of a city that the Romans called Sera Metropolis, which is modern Chang'an. Although the name Sinae appears to be derived from the same etymological source as the Latin prefixes Sino- and Sin-, which are traditionally used to refer to China and the Chinese, there is some controversy as to the ultimate origin of these terms, as their use in historical texts of classical antiquity in the West appears to antedate the emergence of the Qin Dynasty and its empire, the name of which has often been cited as the source of Latin Sino- and Sin-.

Source: Wikipedia