RADIAN - Definition

Pronunciation:		'reydeeun
WordNet Dictionary

	Definition:	[n] the unit of plane angle adopted under the System International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees)

	Websites:

	Synonyms:	rad

	See Also:	angular unit, milliradian

Webster's 1913 Dictionary

	Definition:	\Ra"di*an\, n. [From {Radius}.] (Math.) An arc of a circle which is equal to the radius, or the angle measured by such an arc.