caliber

noun

cal·​i·​ber ˈka-lə-bər 

British also kə-ˈlē-

variants or calibre

1

a

: degree of mental capacity or moral quality

teachers of high caliber

b

: degree of excellence or importance

the caliber of instruction

2

a

: 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

Synonyms of caliber

• quality
• rate

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

Santa Clara has the foundation in place to fill the void atop the league thanks to a high-caliber coach, Sendek, who has sound financial backing for the talent acquisition process. —Jon Wilner, Mercury News, 27 Mar. 2026

The Marlins’ Triple A pitching staff is loaded with White, Snelling, Dax Fulton, Braxton Garrett, Ryan Gusto, William Kempner and at least five big-league-caliber relievers (including Cabe Gibson and Jack Ralston). —Barry Jackson, Miami Herald, 25 Mar. 2026

Each round can weigh upwards of 100 pounds, depending on the particular caliber used. —Mack Degeurin, Popular Science, 25 Mar. 2026

Aleksander Barkov, David Pastrnak and MacKinnon are obviously the dream curve to follow, but there is some separation here between those three MVP-caliber players and Robertson. —Shayna Goldman, New York Times, 25 Mar. 2026

Word History

Etymology

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

First Known Use

1588, in the meaning defined at sense 2b

Rhymes for caliber

• excalibur

Kids Definition

caliber

noun

cal·​i·​ber

variants or calibre

ˈkal-ə-bər 

1

: degree of excellence or importance

2

: the diameter of a missile (as a bullet)

3

: the inside diameter of a gun barrel

Medical Definition

caliber

noun

cal·​i·​ber

variants or chiefly British calibre

ˈkal-ə-bər, British also kə-ˈlē-

: the diameter of a round or cylindrical body

especially : the internal diameter of a hollow cylinder