We don't have synonyms for sering yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are spring, string and sewing.
(n) :
(historical or archaic, uncountable, collective) Synonym of Chinese or Northern Chinese, chiefly in the context of ancient Greco-Roman knowledge of China.
(n) :
(historical or archaic, uncountable, collective) Synonym of Chinese or Northern Chinese, chiefly in the context of ancient Greco-Roman knowledge of China.