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

And so far, things seem to be operating smoothly — something local residents have grown to expect, given the high caliber of local elections officials and the careful oversight of political parties. — Orlando Sentinel Editorial Board, The Orlando Sentinel, 22 Oct. 2026

Its eventual output will help determine how much of the country’s large-caliber weapons demand domestic industry can meet. — Aamir Khollam, Interesting Engineering, 22 Oct. 2026

The caliber’s defining feature is its patented double balance wheel mechanism, which incorporates two balance wheels and two hairsprings assembled on the same axis. — Taylor Stoddard, Robb Report, 21 Oct. 2026

In the years since, the San Bernardino County venue has attracted crowds by booking high-caliber acts like the Smashing Pumpkins, Mariah Carey, the Killers, Ed Sheeran and more. — Andrea Flores, Los Angeles Times, 20 Oct. 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