caliber
n//ˈkæl.ə.bə(ɹ)//kaliber
Unit of measure used to express the length of the bore of a weapon. The number of calibres is determined by dividing the length of the bore of the weapon, from the breech face of the tube to the muzzle, by the diameter of its bore. A gun tube the bore of which is 40 feet (480 inches) long and 12 inches in diameter is said to be 40 calibers long.
(figuratively) Capacity or compass of mind.