Definition from Wiktionary, the free dictionary
- A city in northern California, and the county seat of Humboldt County.
- A city in Illinois, and the county seat of Woodford County.
- A city in Kansas.
- A city in Missouri.
- A town in Montana.
- A census-designated place in Nevada, and the county seat of Eureka County.
- A town in North Carolina.
- A community in Nova Scotia, Canada
- A research base in Nunavut
- A city in South Dakota.
- A city in Texas.
- A city in Utah.
- A town in Wisconsin.
- a given name, like for the protagonists of Wikipedia:Eureka's Castle or Wikipedia:Eureka Seven