Radian

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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

From WordNet (r) 2.0 [wn]:



  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}]