Sinitic
Concise Oxford English Dictionary © 2008 Oxford University Press:
Sinitic /sɪˈnɪtɪk/
▶adjective relating to or denoting the division of the Sino-Tibetan language family that includes the many forms of Chinese.
– origin C19: via late L. from Gk sinai ‘the Chinese’, from Arab. ṣīn, denoting the Chinese empire.
'Sinitic' also found in these Oxford entries:

