from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The diameter of the inside of a round cylinder, such as a tube.
  • noun 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.
  • noun The diameter of a large projectile, such as an artillery shell, measured in millimeters or in inches.
  • noun Degree of worth; quality.

from The Century Dictionary.

  • In gunnery, to ascertain the caliber of; calibrate. See caliper.
  • noun The diameter of a body, especially of the hollow inside of a cylinder: as, the caliber of a piece of ordnance or other firearm.
  • noun Figuratively, compass or capacity of mind; the extent of one's intellectual endowments.
  • noun In horology: The distance between the two plates of a watch which determines the flatness of the movement.
  • noun The plate upon which is traced the arrangement of the pieces of a clock; the pattern-plate.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Gunnery) The diameter of the bore, as a cannon or other firearm, or of any tube; or the weight or size of the projectile which a firearm will carry.
  • noun The diameter of round or cylindrical body, as of a bullet or column.
  • noun Fig.: Capacity or compass of mind.
  • noun See Calipers.
  • noun a gunner's calipers, an instrument having two scales arranged to determine a ball's weight from its diameter, and conversely.
  • noun the weight of her armament.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun US spelling of calibre.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a degree or grade of excellence or worth
  • noun diameter of a tube or gun barrel


from The American Heritage® Dictionary of the English Language, 4th Edition

[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.]


Help support Wordnik (and make this page ad-free) by adopting the word caliber.



Log in or sign up to get involved in the conversation. It's quick and easy.