Ar·i·zo·na (ār'ĭ-zō'nə) A state of the southwest United States on the Mexican border. It was admitted as the 48th state in 1912. Explored by the Spanish beginning in 1539, the area was acquired by the United States in 1848 through the Treaty of Guadalupe Hidalgo. Phoenix is the capital and the largest city. Population: 6,340,000. Ar'i·zo'nan, Ar'i·zo'ni·an adj. & n.
State in the southwestern United States bordered by Utah to the north, New Mexico to the east, Mexico to the south, and California and Nevada to the west. Its capital and largest city is Phoenix.
Note: The Grand Canyon is in northwestern Arizona.