the diameter of something of circular section, especially that of the inside of a tube: a pipe of three-inch caliber.
Ordnance. the diameter of the bore of a gun taken as a unit of measurement.
degree of capacity or competence; ability: a mathematician of high caliber.
degree of merit or excellence; quality: the high moral caliber of the era.

Also especially British, cal·i·bre.

Origin of caliber

1560–70; variant of calibre < Middle FrenchArabic qālib mold, last < Greek kālápous shoe last, equivalent to kāla- combining form of kâlon wood + poús foot (see -pod)
Related formscal·i·bered; especially British, cal·i·bred, adjective

Synonyms for caliber Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for calibre

Contemporary Examples of calibre

Historical Examples of calibre

  • It is such an enterprise as should please a ready swordsman of your calibre, Fortunio.

    St. Martin's Summer

    Rafael Sabatini

  • It is a relief to have an outsider of Hankey's calibre on the spot.

  • He could well afford to be lenient to a rebel of his calibre.

  • Grandeur, even in infamy, is utterly inconsistent with the calibre of the man.

  • All the same, I am not very sweet on love matches for men of Orange's calibre.

    Robert Orange

    John Oliver Hobbes

British Dictionary definitions for calibre


US caliber


the diameter of a cylindrical body, esp the internal diameter of a tube or the bore of a firearm
the diameter of a shell or bullet
ability; distinctiona musician of high calibre
personal charactera man of high calibre
Derived Formscalibred or US calibered, adjective

Word Origin for calibre

C16: from Old French, from Italian calibro, from Arabic qālib shoemaker's last, mould
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for calibre

chiefly British English spelling of caliber (q.v.); for spelling, see -re.



1560s, "degree of merit or importance," a figurative use from Middle French calibre (late 15c.), apparently ultimately from Arabic qalib "a mold for casting." Arabic also used the word in the sense "mold for casting bullets," which is the oldest literal meaning in English. Meaning "inside diameter of a gun barrel" is attested from 1580s. Barnhart remarks that Spanish calibre, Italian calibro "appear too late to act as intermediate forms" between the Arabic word and the French.

Online Etymology Dictionary, © 2010 Douglas Harper

calibre in Medicine




The diameter of the inside of a round cylinder, such as a tube.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.