circumference

noun

cir·​cum·​fer·​ence sər-ˈkəm(p)-f(ə-)rən(t)s How to pronounce circumference (audio)
sə-,
-fərn(t)s
1
: the perimeter of a circle
The circle measures 22 inches in circumference.
2
: the external boundary or surface of a figure or object : periphery
from the center to the circumference of the sphere
circumferential adjective

Did you know?

Attempts have been made to measure the circumference of the earth since the time of Aristotle. The calculation that Columbus was relying on led him to think he could reach China by sailing west more quickly than by sailing east. But that measurement had calculated the earth's circumference as about a quarter too small, and the rest is history. Columbus wasn't the only one who got it wrong; many later attempts continued to produce different measurements for the earth's circumference—even though the Greeks had calculated it correctly way back in the 3rd century B.C.

Examples of circumference in a Sentence

What is the circumference of the Earth at the equator? The circle is 38 inches in circumference. The fence marks the circumference of the field.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Tree nominees are judged on trunk circumference, vertical height and crown spread. Jennie Key, The Enquirer, 31 Aug. 2025 Flaxseed may also help reduce waist circumference in people with obesity. Brittany Lubeck, Verywell Health, 27 Aug. 2025 Max Baum/Steffen Köhler To assess the changes wrought by the acidity, scientists measured the circumference of the teeth before and after incubation. Melissa Fleur Afshar, MSNBC Newsweek, 27 Aug. 2025 Measure Cup and Make Pattern Measure the height and circumference of your favorite coffee cup or jar. Claire Hoppe Norgaard, Better Homes & Gardens, 26 Aug. 2025 See All Example Sentences for circumference

Word History

Etymology

Middle English, from Middle French & Latin; Middle French, from Latin circumferentia, from circumferre to carry around, from circum- + ferre to carry — more at bear

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of circumference was in the 14th century

Browse Nearby Words

Cite this Entry

“Circumference.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/circumference. Accessed 9 Sep. 2025.

Kids Definition

circumference

noun
cir·​cum·​fer·​ence sə(r)-ˈkəm(p)-fərn(t)s How to pronounce circumference (audio)
-f(ə-)rən(t)s
1
: a line that goes around or encloses a circle
2
: the outer boundary of a figure or area
3
: the distance around something
the circumference of the earth at the equator

More from Merriam-Webster on circumference

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!