Eureka (word)
The exclamation 'Eureka!' is attributed to the ancient Greek scholar Archimedes. He reportedly proclaimed "Eureka! Eureka!" after he had stepped into a bath and noticed that the water level rose, whereupon he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. (This relation is "not" what is known as Archimedes' principle—that deals with the "upthrust" experienced by a body immersed in a fluid.) He then realized that the volume of irregular objects could be measured with precision, a previously intractable problem. He is said to have been so eager to share his discovery that he leapt out of his bathtub and ran naked through the streets of Syracuse.
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".