a large, black European wild ox, Bos primigenius: extinct since 1627.
2.
(not used scientifically) the European bison.
Origin: 1760–70; < German, variant (now obsolete) of Auerochs,Middle High Germanūrochse,Old High Germanūrohso, equivalent to ūr (cognate with Old Englishūr bison) + ohsoox
Also called: urus a recently extinct member of the cattle tribe, Bos primigenius, that inhabited forests in N Africa, Europe, and SW Asia. It had long horns and is thought to be one of the ancestors of modern cattle
[C18: from German, from Old High German ūrohso, from ūro bison + ohsoox]
1766, misapplication to the European bison (Bos Bison) of a word that actually refers to a species of wild ox (Bos Ursus) that went extinct 17c., from Ger. Aurochs, from O.H.G. urohso, from uro "aurochs" (cognate with O.E. ur, O.N. ürr), of unknown origin, + ohso "ox" (see