Eureka, California
"Eureka" received its name from a Greek word meaning "I have found it!" This exuberant statement of successful (or hopeful) gold rush miners is also the official motto of the State of California. Eureka is the only U.S. location to use the same seal as the state for its seal.
Púca
The origin of the name may have come from the Old Norse term "pook" or "puki", which refers to a "nature spirit". Usage of the term in Ireland, however, may predate the arrival of Norse settlers.
In Germanic languages, such as Frisian or English, this became "pucel", "pook" or "puck". The name of the pooka may also come from the Irish word "poc", meaning a male goat, a form the creature is often said to take.