# radian

## noun

ra·​di·​an
: a unit of plane angular measurement that is equal to the angle at the center of a circle subtended by an arc whose length equals the radius or approximately 57.3 degrees

## Examples of radian in a Sentence

Recent Examples on the Web At the 2024 Six Nations Championship, on-field doctors were flagged when a player’s mouthguard registered an acceleration above 70 g’s and 4,500 radians per second squared (rad/s2). Jeffrey Tomik, Washington Post, 2 Apr. 2024 So angular velocity measures the angle that the ball covers (in radians per second). Rhett Allain, WIRED, 2 Feb. 2024 This puts the angular velocity at 93.65 radians per second. Adam Rogers, WIRED, 10 July 2019 These units are called radians (apologies if this term provokes a violent and sickening flashback to high school math), and there are 2π of them in a circle. Brian Resnick, Vox, 13 Mar. 2019 Three quarters around the same circle has gone one and a half pi radians. Randyn Charles Bartholomew, Scientific American, 25 June 2014 According to People, the elongated radian cut ring is 4 carats, and was personally designed by Zandy along with Leor Yerushalmi and The Jewelers of Las Vegas. De Elizabeth, Teen Vogue, 29 Apr. 2018 For example, pi can be measured according to radians, the standard unit for angular measurements. Jay Bennett, Popular Mechanics, 14 Mar. 2018 Radian was required to set aside reserves against potential losses on bad loans, and Mr. Lutz reckoned that his employer was materially understating those amounts. Gretchen Morgenson, New York Times, 28 Apr. 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'radian.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

## Word History

First Known Use

1879, in the meaning defined above

Time Traveler
The first known use of radian was in 1879

radian

## Cite this Entry

“Radian.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radian. Accessed 14 Sep. 2024.

## Medical Definition

radian

noun
ra·​di·​an
: a unit of plane angular measurement that is equal to the angle at the center of a circle subtended by an arc equal in length to the radius

## More from Merriam-Webster on radian

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