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

Researchers also measured body weight, waist circumference, body composition, and fasting levels of several hormones involved in appetite regulation.

From Science Daily ● Jul. 13, 2026

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

These may include direct measures of body composition or simpler alternatives such as skinfold measurements or body circumference indicators like the waist-to-height ratio.

From Science Daily ● Apr. 3, 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

He motioned for the others to follow him and slipped around the circumference of the rotunda.

From "Escape from Mr. Lemoncello's Library" by Chris Grabenstein

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

From Washington Times ● Mar. 10, 2023

Helmet sizes are measured by head circumference, and helmets usually come with adjustable dials to accommodate a range of circumferences.

From Washington Post ● Mar. 21, 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

Or, more in agreement with Euclid’s form:— Two different circles, whose circumferences have a point in common, cannot have the same centre.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

Related Words

• girth