circumference
Americannoun
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the boundary of a specific area or geometric figure, esp of a circle
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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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The boundary line of a circle.
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The boundary line of a figure, area, or object.
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The length of such a boundary. The circumference of a circle is computed by multiplying the diameter by pi.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
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.
Vocabulary lists containing circumference
100 Words Every Middle Schooler Should Know
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Essential Academic Vocabulary for Middle School Students, List 1
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Pi Day Vocabulary
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
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
On average, the intervention group lost 3.3 kg and reduced waist circumference by 3.6 cm.
From Science Daily ● May 19, 2026
Waist circumference also dropped more sharply with semaglutide, decreasing by an average of −14.3 cm versus −6.0 cm with placebo.
From Science Daily ● May 11, 2026
In a phase 2 trial in Chinese patients with Type 2 diabetes, UBT251 also showed a mean blood sugar reduction of up to 2.16% while improving patient’s waist circumference and blood pressure.
From The Wall Street Journal ● Mar. 25, 2026
“I hope you’re hungry. My head has a circumference of twenty-four inches,” Petra shouted over the wind, and they all laughed.
From "Beauty Queens" by Libba Bray
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
She held up her bit of paper as she spoke, scrawled over with intersecting circles and arcs and ellipses, against whose curves and circumferences she had written names: Marchbanks, Hadden, Goldthwaite, Holabird.
From We Girls: a Home Story by A. D. T. (Adeline Dutton Train) Whitney
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
