circumference

noun

cir·​cum·​fer·​ence sər-ˈkəm(p)-f(ə-)rən(t)s 

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

sər-ˌkəm(p)-fə-ˈren(t)-shəl 

sə-

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.

Synonyms

• girth

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

The Tribune printed a map showing the circumference of locations from which Wiedersberg’s climb would be easily visible to the naked eye. —Marianne Mather, Chicago Tribune, 7 Nov. 2024

But size, the right thickness vs. circumference, density, the perfect proof time, plus the right amount of blistering and oil are equally important. —Karri Peifer, Axios, 3 Oct. 2024

According to Guinness, a cyclist must travel in the same direction, start and end in the same place, and rack up at least 18,000 miles – the total circumference of the globe – for a round-the-world attempt to be successful. —Jamie Barton, CNN, 12 Sep. 2024

Their calculations focused on building shield rings that would have a radius of 50 meters (164 ft), a circumference of 314 m (1,030 ft) and a height of 3.3 m (10.8 ft). —Michael Franco, New Atlas, 6 Aug. 2024

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

Kids Definition

circumference

noun

cir·​cum·​fer·​ence sə(r)-ˈkəm(p)-fərn(t)s 

-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