The fact is no one really knows for sure, but there are several theories. One claims that Arizona was taken from the Pima Indian word Arizonac, meaning “little spring place.” However furthur research traces this back to an inaccurate map of Early Southern Arizona, so it was not likely the true origin.
Another is the Papago, Ali-Shonak meaning “small spring.” This was used to describe Planchas de Plata, where the huge silver strike was found nearby Nogales. The miners thought it sounded like Arissona.
Still another is a play on the Spanish phrase meanining “arid zone,” Arida Zona. The correct saying is Zona Arida, so many believe this is just a coincidence, but it is possible that some clever phrasing and relation to other similar Indian terms helped solidify the Arizona name.
But perhaps the best case for where the Arizona name came from is the Arizona ranch settlement. This was a small area in modern day Southern Arizona that was settled by early Spanish ranchers and Basque people. Arizona in Basque translates to “good oak tree.” In fact there are cities named Arizona in Brazil, Honduras, Costa Rica, Guatemala and other countries.
Arizona’s name became official when it seceded from New Mexico (yes it was originally all New Mexico) and became it’s own territory in 1861. Many names were considered including Pimeria, Gadsonia and Arizuma. Ultimately the name became Arizona and the rest is history.