Meaning

noun European bison having a smaller and higher head than the North American bison

noun large recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle

originBorrowed from German Aurochs, an early variant of Auerochse, from Middle High German ūrochse (“aurochs”), from Old High German ūrohso (“aurochs”), a compound consisting of ūro (“aurochs”) (from Proto-Germanic *ūraz, *ūrô (“aurochs”)) + ohso (“ox”). Akin to Old English ūr (“aurochs”), Old Norse úrr (“aurochs”), Middle Low German ūrosse (“aurochs”), Old English oxa (“ox”). More at ox.

Etymology from Wiktionary, CC BY-SA 3.0