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

• class
• grade
• 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

Inside his small bedroom, officers found 20 firearms of various calibers, along with about 10,000 rounds of ammunition — also of various calibers — as well as 2 pounds of gunpowder and a polyvinyl chloride pipe bomb with a red-colored fuse, according to the warrant. —David Goodhue, Miami Herald, 19 Mar. 2025

However, this caliber — like all calibers previously used within the Overseas line — was based upon an ébauche from a third party. —Oren Hartov, Robb Report, 18 Mar. 2025

Even if Flagg returns healthy, Duke hasn’t faced many top-25 caliber teams since conference play started. —Scott Phillips, The Athletic, 17 Mar. 2025

Both of those teams have big league caliber prospects to send to San Diego in exchange for Cease. —Faisal Kutty, Newsweek, 12 Mar. 2025

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