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

That leaves them time to maximize their potential more gradually as possible All-Star caliber players. — Mark Medina, Forbes.com, 23 June 2026

It’s been 16 years since a player of this caliber took his talents to South Beach, but that time the Heat were able to pair LeBron James with Dwyane Wade and Chris Bosh en route to four straight finals and two titles. — John Hollinger, New York Times, 23 June 2026

No one was injured, and police said the caliber and source of the bullet remain under investigation as developers hire security patrols after construction trailers in the area were also hit. — Chadd Cripe. Produced With Ai Assistance, Idaho Statesman, 23 June 2026

The 6-foot-3 winger, drafted 36th overall by the Sharks in 2023, has an NHL-caliber shot and was developing more of an all-around game at the AHL level, but was likely not going to crack the Sharks’ roster out of this fall’s training camp. — Curtis Pashelka, Mercury News, 23 June 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