Found 2 items, similar to radian.
English → English (WordNet) Definition: radian radian n : the unit of plane angle adopted under the Systeme 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) [syn: rad]
English → English (gcide) Definition: Radian Radian \Ra"di*an\ (r[=a]"d[i^]*an), n. [From Radius.] (Math.) An arc of a circle which is equal to the radius, or the angle measured by such an arc. [1913 Webster]