circumference

American  

[ser-kuhm-fer-uhns] / sərˈkʌm fər əns /

noun

circumferences plural

1. the outer boundary, especially of a circular area; perimeter.

   the circumference of a circle.

   Synonyms:

   circuit, periphery

2. the length of such a boundary.

   a one-mile circumference.

3. the area within a bounding line.

   the vast circumference of his mind.

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circumference British  

/ səˌkʌmfəˈrɛnʃəl, səˈkʌmfərəns /

noun

1. the boundary of a specific area or geometric figure, esp of a circle

2. the length of a closed geometric curve, esp of a circle. The circumference of a circle is equal to the diameter multiplied by π

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circumference Scientific  

/ sər-kŭm′fər-əns /

1. The boundary line of a circle.

2. The boundary line of a figure, area, or object.

3. The length of such a boundary. The circumference of a circle is computed by multiplying the diameter by pi.

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circumference Cultural  

1. The measure of the distance around a circle.

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Other Word Forms

Derived Forms

• circumferential
  adjective
• circumferentially
  adverb

Inflected Forms

Nouns

• circumferences
  plural

Etymology

Origin of circumference

1350–1400; Middle English < Late Latin circumferentia, equivalent to circum- circum- + fer- (stem of ferre to carry) + -entia -ence

Explanation

The distance around a circle is called the circumference, and although circumference is often used when talking about round things, it can mean a boundary of any shape that completely surrounds something. It’s no coincidence that the first part of circumference looks like circle. The Latin word circum means “around,” and the root ferre is the Latin verb for “carry,” so imagine carrying a puppy around a circle pit of lava: the path you walk is the circumference. If you want to buy a new hat, you’ll need to measure the circumference of your head, and patrolling the circumference of your castle is a good way to protect against dragons.

Example Sentences

See Examples For:

circumference circumferences

And it was a nerve-shredding putt from inside three feet that travelled most of the circumference of the hole before dropping that deservedly saw Korda home.

From BBC ● Jun. 8, 2026

Average body weight was 99.0 kg, average BMI was 36.6 kg/m², and average waist circumference was 115 cm.

From Science Daily ● May 11, 2026

Patients also showed improvements relative to placebo on key secondary goals of the trial including waist circumference, blood glucose and blood pressure, they added.

From The Wall Street Journal ● Feb. 24, 2026

UBT251 led to a mean weight loss of 19.7% after 24 weeks of treatment and also improved patients’ waist circumference, blood glucose, blood pressure, and lipids relative to placebo, the companies said.

From Barron's ● Feb. 24, 2026

The site is, I am told by my friend Jeff Guinn of the Fort Worth Star-Telegram, "essentially a vast, cleared field dotted along the circumference by a series of disappointed small towns."

From "A Short History of Nearly Everything" by Bill Bryson

The helmets are marked as large, for head circumferences between 22.5 to 25 inches.

From Washington Times ● Mar. 10, 2023

Drips are indulged, or even encouraged, and rings of painted dots often trace the circumferences of larger orbs.

From Washington Post ● Dec. 30, 2022

During an inspection Dec. 15, Sampson observed “numerous” branches with 2- to 8-inch circumferences that were severed by the aerial saw and allowed to fall from 150 feet above, according to the violation notice.

From Los Angeles Times ● Mar. 2, 2022

A meager set is a set contained in the countable union of nowhere dense sets, such as the circumference of a circle in the plane, or finitely or countably many such circumferences.

From Scientific American ● Aug. 16, 2021

Thus the power applied to the axle is carried at once to the parts of the wheels of least stress—the circumferences.

From The Mirror Of Literature, Amusement, And Instruction Volume 14, No. 391, September 26, 1829 by Various

Related Words

• girth