radian

2 definitions found

radian - Collaborative International Dictionary of English v.0.48 :

  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] Radiance

radian - WordNet (r) 2.1 (2005) :

  radian
      n 1: 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: radian, rad]