Eureka (word)
"Eureka" comes from the Ancient Greek word "heúrēka", meaning "I found (it)", which is the first person singular perfect indicative active of the verb "heuriskō" "I find". It is closely related to heuristic, which refers to experience-based techniques for problem solving, learning, and discovery.
Aurochs
The words aurochs, urus, and wisent have all been used synonymously in English. But the extinct aurochs/urus is a completely separate species from the still-extant wisent, also known as European bison. The two were often confused, and some 16th-century illustrations of aurochs and wisents have hybrid features.
The word "urus" (; plural "uri") is a Latin word, but was borrowed into Latin from Germanic (cf. Old English/Old High German "ūr", Old Norse "úr"). In German, OHG "ūr" was compounded with "ohso" "ox", giving "ūrohso", which became early modern "Aurochs". The modern form is "Auerochse".