bison (n.) Look up bison at Dictionary.com
c. 1600, from French bison (15c.), from Latin bison "wild ox," borrowed from Proto-Germanic *wisand- "aurochs" (source also of Old Norse visundr, Old High German wisunt "bison," Old English/Middle English wesend, which is not attested after c. 1400). Possibly ultimately of Baltic or Slavic origin, and meaning "the stinking animal," in reference to its scent while rutting (see weasel). A European wild ox formerly widespread on the continent, including the British Isles, now surviving on forest reserves in Lithuania. Applied 1690s to the North American species commonly mis-called a buffalo.