diameter
noun
di·am·e·ter
dī-ˈa-mə-tər 
1
mathematics
: a chord (see chord entry 3 sense 2) passing through the center of a figure or body
2
mathematics
: the length of a straight line through the center of an object or space
the diameter of a circle
dug a hole nearly four feet in diameter
3
physics
: a unit of enlargement used with a number to indicate magnification by a lens or optical system
an object one millimeter wide magnified 40 diameters appears 40 millimeters wide
Examples of diameter in a Sentence
The dotted line indicates the diameter of the circle.
What is the diameter of the tree trunk?
Dig a hole that's two feet deep and three feet in diameter.
Recent Examples on the Web
By comparison, a strand of human DNA is 2.5 nanometers in diameter and a human hair is approximately 80,000 - 100,000 nanometers wide, the Initiative states.
—
USA TODAY, 23 Apr. 2024
The stronger storms will be capable of producing damaging winds and large hail, ranging up to 1.75 inches in diameter, the weather service said.
—Robert A. Cronkleton, Kansas City Star, 17 Apr. 2024
The object that survived the reentry is made of the metal alloy Inconel, and weighs around 1.6 pounds, is 4 inches in height, and 1.6 inches in diameter, according to NASA.
—Passant Rabie / Gizmodo, Quartz, 16 Apr. 2024
The object, made of a metal alloy, weighs 1.6 lbs., is four inches tall and 1.6 inches in diameter.
—Abigail Adams, Peoplemag, 16 Apr. 2024
Hail as big as golf balls — which are 1.68 inches in diameter and more likely to leave dents in vehicles — was reported near Brambleton in southeast Loudoun County.
—Dan Stillman, Washington Post, 16 Apr. 2024
In the mid-Atlantic, a severe thunderstorm watch was issued for parts of West Virginia, Virginia, Maryland and Delaware until 10 p.m.
Storms were starting to develop as of Monday afternoon and may produce damaging winds that could reach 70 mph and scattered hail as large as 2 inches in diameter.
—Erin McGarry, NBC News, 15 Apr. 2024
To the right of the foyer, the circular combination living and dining room has a 36-foot diameter, and at 1,100 square feet (larger than most New York City apartments!), there’s plenty of space to accommodate a billiards table, a small desk, and a bar, along with ample lounging and dining areas.
—Emma Reynolds, Robb Report, 15 Apr. 2024
Take a look → Mysterious wooden train car — almost 100 years old — unearthed in Belgium, photos show
Weighing nearly 30 grams with a diameter of 4 centimeters, the coin had the depictions of two princes on each side, the museum said.
—Irene Wright, Miami Herald, 10 Apr. 2024
USA TODAY, 23 Apr. 2024
The stronger storms will be capable of producing damaging winds and large hail, ranging up to 1.75 inches in diameter, the weather service said.
—Robert A. Cronkleton, Kansas City Star, 17 Apr. 2024
The object that survived the reentry is made of the metal alloy Inconel, and weighs around 1.6 pounds, is 4 inches in height, and 1.6 inches in diameter, according to NASA.
—Passant Rabie / Gizmodo, Quartz, 16 Apr. 2024
The object, made of a metal alloy, weighs 1.6 lbs., is four inches tall and 1.6 inches in diameter.
—Abigail Adams, Peoplemag, 16 Apr. 2024
Hail as big as golf balls — which are 1.68 inches in diameter and more likely to leave dents in vehicles — was reported near Brambleton in southeast Loudoun County.
—Dan Stillman, Washington Post, 16 Apr. 2024
In the mid-Atlantic, a severe thunderstorm watch was issued for parts of West Virginia, Virginia, Maryland and Delaware until 10 p.m.
Storms were starting to develop as of Monday afternoon and may produce damaging winds that could reach 70 mph and scattered hail as large as 2 inches in diameter.
—Erin McGarry, NBC News, 15 Apr. 2024
To the right of the foyer, the circular combination living and dining room has a 36-foot diameter, and at 1,100 square feet (larger than most New York City apartments!), there’s plenty of space to accommodate a billiards table, a small desk, and a bar, along with ample lounging and dining areas.
—Emma Reynolds, Robb Report, 15 Apr. 2024
Take a look → Mysterious wooden train car — almost 100 years old — unearthed in Belgium, photos show
Weighing nearly 30 grams with a diameter of 4 centimeters, the coin had the depictions of two princes on each side, the museum said.
—Irene Wright, Miami Herald, 10 Apr. 2024
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'diameter.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near diameter
Cite this Entry
“Diameter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diameter. Accessed 27 Apr. 2024.
Copy CitationKids Definition
diameter
noun
di·am·e·ter
dī-ˈam-ət-ər
1
: a straight line passing through the center of a figure or body
especially
: a line segment through the center of a circle with its ends on the circle's circumference
2
: the length of a diameter
Medical Definition
diameter
noun
di·am·e·ter
dī-ˈam-ət-ər
1
: a unit of magnification for an optical instrument equal to the number of times the linear dimensions of an object are apparently increased
a microscope magnifying 60 diameters
2
: one of the maximal breadths of a part of the body
the transverse diameter of the inlet of the pelvis
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