Synonyms for Aurochs (same or very similar meaning)
WordNet sense 1 (European bison having a smaller and higher head than the North American bison):
wisent, Bison bonasusWordNet sense 2 (large recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle):
urus, Bos primigeniusFrom the ODE community, based on WordNetadd/edit