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

But even as currently constructed with those concerns, this looks like a playoff-caliber team. — Shayna Goldman, New York Times, 4 Sep. 2026

His front row was the stuff of fashion mythology, the kind of group that could only be summoned by a muse collector of Ackermann’s caliber. — José Criales-Unzueta, Vanity Fair, 2 Sep. 2026

Powered by the manual wound caliber DR002, the watch is priced at a cool $76,500. — Carol Besler, Robb Report, 2 Sep. 2026

Hair caliber, curl and color contrast change the coverage created by each follicular unit. — Malana Vantyler, Kansas City Star, 2 Sep. 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