Source : Webster's Revised Unabridged Dictionary (1913)

Rad \Rad\, obs.
   imp. & p. p. of {Read}, {Rede}. --Spenser.

Source : WordNet®

rad
     n 1: a unit of absorbed ionizing radiation equal to 100 ergs per
          gram of irradiated material
     2: 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}]

Source : Free On-Line Dictionary of Computing

RAD
     
         {Rapid Application Development}.