Sino-Xenic vocabularies are large-scale and systematic borrowings of the Chinese lexicon into the Japanese, Korean and Vietnamese languages, none of which are genetically related to Chinese. The resulting Sino-Japanese, Sino-Korean and Sino-Vietnamese vocabularies now make up a large part of the lexicons of these languages. The pronunciation systems for these vocabularies originated from conscious attempts to consistently approximate the original Chinese sounds while reading Classical Chinese. They are used alongside modern varieties of Chinese in historical Chinese phonology, particularly the reconstruction of the sounds of Middle Chinese.[1][2] Some other languages, such as Hmong–Mien and Kra–Dai languages, also contain large numbers of Chinese loanwords but without the systematic correspondences that characterize Sino-Xenic vocabularies.
The term, from the Greek ξένος (xénos, 'foreign'), was coined in 1953 by the linguist Samuel Martin, who called these borrowings "Sino-Xenic dialects".[2][3][4]