The diameter of the inside of a round cylinder, such as a tube.
The diameter of the bore of a firearm, usually shown in hundredths or thousandths of an inch and expressed in writing or print in terms of a decimal fraction: .45 caliber.
The diameter of a large projectile, such as an artillery shell, measured in millimeters or in inches.
Degree of worth; quality: a school of high caliber; an executive of low caliber.
[French calibre, from Italian calibro, from Arabic qālib, qālab, mold, shoe tree, from Greek kālapous, shoemaker's last : kālon, wood + pous, foot; see ped- in Indo-European roots.]
Cal·i·for·nia (kāl'ĭ-fôr'nyə, -fôr'nē-ə) Abbr. CA or Cal. or Calif. A state of the western United States on the Pacific Ocean. It was admitted as the 31st state in 1850. The area was colonized by the Spanish and formally ceded to the United States by the Treaty of Guadalupe Hidalgo (1848). California is often called the Golden State because of its sunny climate and the discovery of gold during its pioneering days. Sacramento is the capital and Los Angeles the largest city. Population: 36,600,000. Cal'i·for'nian adj. & n.