cal·​i·​ber | \ ˈka-lə-bər How to pronounce caliber (audio) , British also kə-ˈlē-\
variants: or calibre

Definition of caliber

1a : degree of mental capacity or moral quality teachers of high caliber
b : degree of excellence or importance the caliber of instruction
2a : the diameter of a bullet or other projectile
b : the diameter of a bore of a gun usually expressed in hundredths or thousandths of an inch and typically written as a decimal fraction .32 caliber
3 : the diameter of a round or cylindrical body especially : the internal diameter of a hollow cylinder

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Synonyms for caliber


class, grade, quality, rate

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Examples of caliber in a Sentence

I was impressed by the high caliber of the team's work. musicians of the highest caliber perform at that concert hall

Recent Examples on the Web

Law-enforcement officials named Long on Thursday as the man who killed 12 people with a .45 caliber pistol. Sara Randazzo, WSJ, "California Bar Shooter Had Domestic-Disturbance History After Serving in Afghanistan," 8 Nov. 2018 Like with similar buybacks in 2013 and 2015, Saturday’s event brought in a wide array of weapons, including small-caliber pistols and antique rifles. Alex Nitkin,, "Dozens of guns taken by Evanston police at 'no questions asked' buyback event," 11 June 2018 Galveston County Jail The Houston Chronicle reported that the assailant was armed with a .38 caliber pistol, a shotgun and pipe bombs. Matthew Martinez, star-telegram, "Suspected shooter identified: What we know about the Santa Fe, Texas, school shooting | Fort Worth Star-Telegram," 18 May 2018 Police found a loaded .45 caliber semiautomatic pistol under the seat where Smith had been sitting, according to the release. Staff Report, Aurora Beacon-News, "Aurora man convicted on gun charge," 16 May 2018 Blood stains were on his clothes, and police found plastic zip ties, two cell phones, a Glock .40 caliber pistol and blood on the ground stretching from the apartment to the field, police said. Samantha Ketterer, Houston Chronicle, "Four accused in fatal shooting after robbery in Pasadena," 14 May 2018 The two men accused each other of cutting the other off, when Leibiger allegedly went into his car and pulled a .45 caliber Glock pistol from his center console and pointed it at the victim, the complaint said. Tyler Langan, Milwaukee Journal Sentinel, "Sussex man allegedly pulls gun in 'road rage' incident in Menomonee Falls," 24 Apr. 2018 Police on Tuesday fatally shot a man armed with a .45 caliber pistol who was trying to break into rooms at the Embassy Suites hotel in downtown San Antonio, officials said. Caleb Downs, San Antonio Express-News, "Police fatally shoot man at downtown San Antonio hotel," 24 Apr. 2018 Hall, 53, is a soft-spoken snow-removal worker with a slight paunch, a salt-and-pepper beard and a matched set of .45 caliber pistols. Kirk Johnson, The Seattle Times, "Car Stolen in Anchorage? Enter Floyd the Thief Chaser," 13 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'caliber.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of caliber

1588, in the meaning defined at sense 2b

History and Etymology for caliber

borrowed from Middle French calibre "internal diameter of a cylindrical object, displacement of a gun," borrowed (by uncertain mediation) from Arabic qālab, qālib "mold for casting metal, shoemaker's last," borrowed from Greek kalapod-, kalápous, kalópous "shoemaker's last," from kâla (plural) "wood, timber" (of uncertain origin) + -a- (perhaps after tetrápous "four-footed") or -o- -o- + poús "foot" — more at foot entry 1

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Statistics for caliber

Last Updated

10 Mar 2019

Look-up Popularity

Time Traveler for caliber

The first known use of caliber was in 1588

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More Definitions for caliber



English Language Learners Definition of caliber

: level of excellence, skill, etc.
: a measurement of the width of a bullet or a gun barrel


variants: or calibre \ ˈka-​lə-​bər \

Kids Definition of caliber

1 : level of excellence, skill, or importance She is a writer of the highest caliber.
2 : the diameter of a bullet or of the hole in the barrel of a gun


variants: or chiefly British calibre \ ˈkal-​ə-​bər, British also kə-​ˈlē-​ \

Medical Definition of caliber

: the diameter of a round or cylindrical body especially : the internal diameter of a hollow cylinder

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