1738 (adj.) "pertaining to Mongols;" 1839 (n.) "the language of the Mongols," 1846 "a native of Mongolia;" from Mongol + -ian. As a racial classification for Asiatic peoples (including Chinese, Japanese, Turks, Vietnamese, Lapps, Eskimos, etc.) "belonging to the yellow-skinned straight-haired type of mankind" [OED] in J.F. Blumenbach's system, it is attested in English by 1825 in translations of his works.